Slot structure of long physical uplink control channel (PUCCH) design for 5th generation (5G) new radio (NR)

ABSTRACT

A user equipment (UE) is described. The UE includes a processor and memory in electronic communication with the processor. Instructions stored in the memory are executable to determine the uplink control channel (PUCCH) format and configuration based on a signaling from a base station (gNB). The instructions are also executable to determine the demodulation reference signal (DMRS) locations in the configured PUCCH. The instructions are further executable to determine the uplink control information (UCI) multiplexing methods on the configured PUCCH. The instructions are additionally executable to determine the resource of the control channel for UCI feedback. The instructions are also executable to transmit UCI feedback on the selected control channel.

RELATED APPLICATIONS

This application is related to and claims priority from U.S. Provisional Patent Application No. 62/543,757, entitled “SLOT STRUCTURE OF LONG PHYSICAL UPLINK CONTROL CHANNEL (PUCCH) DESIGN FOR 5th GENERATION (5G) NEW RADIO (NR),” filed on Aug. 10, 2017, which is hereby incorporated by reference herein, in its entirety.

TECHNICAL FIELD

The present disclosure relates generally to communication systems. More specifically, the present disclosure relates to the slot structure of long physical uplink control channel (PUCCH) design for 5th generation (5G) new radio (NR).

BACKGROUND

Wireless communication devices have become smaller and more powerful in order to meet consumer needs and to improve portability and convenience. Consumers have become dependent upon wireless communication devices and have come to expect reliable service, expanded areas of coverage and increased functionality. A wireless communication system may provide communication for a number of wireless communication devices, each of which may be serviced by a base station. A base station may be a device that communicates with wireless communication devices.

As wireless communication devices have advanced, improvements in communication capacity, speed, flexibility and/or efficiency have been sought. However, improving communication capacity, speed, flexibility and/or efficiency may present certain problems.

For example, wireless communication devices may communicate with one or more devices using a communication structure. However, the communication structure used may only offer limited flexibility and/or efficiency. As illustrated by this discussion, systems and methods that improve communication flexibility and/or efficiency may be beneficial.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating one implementation of one or more base stations (gNBs) and one or more user equipments (UEs) in which systems and methods for a slot structure of a long physical uplink control channel (PUCCH) design for 5th generation (5G) new radio (NR) may be implemented;

FIG. 2 is a diagram illustrating one example of a resource grid for the downlink;

FIG. 3 is a diagram illustrating one example of a resource grid for the uplink;

FIG. 4 shows examples of several numerologies;

FIG. 5 shows examples of subframe structures for the numerologies that are shown in FIG. 4;

FIG. 6 shows examples of slots and sub-slots;

FIG. 7 shows examples of scheduling timelines;

FIG. 8 shows examples of downlink (DL) control channel monitoring regions;

FIG. 9 shows examples of DL control channel which consists of more than one control channel elements;

FIG. 10 shows examples of uplink (UL) control channel structures;

FIG. 11 is a block diagram illustrating one implementation of a gNB;

FIG. 12 is a block diagram illustrating one implementation of a UE;

FIG. 13 illustrates several examples of long PUCCH duration design;

FIG. 14 illustrates examples of two demodulation reference signals (DMRS) in every 7 symbols for normal cyclic prefix (NCP) or 6 symbols for extended cyclic prefix (ECP);

FIG. 15 illustrates examples of the minimum number of symbols for a long PUCCH;

FIG. 16 illustrates examples of one DMRS in every 7 symbols for NCP or 6 symbols for ECP;

FIG. 17 illustrates fixed hopping candidates for PUCCH based on fixed DMRS patterns;

FIG. 18 illustrates examples of PUCCH DMRS basic blocks in a hop;

FIGS. 19A and 19B illustrate examples of DMRS patterns for different durations;

FIG. 20 illustrates examples of RS patterns with frequency division multiplexing (FDM) among UEs for two DMRS in every 7 symbols for NCP;

FIG. 21 illustrates examples of RS patterns with FDM among UEs for two DMRS in every 6 symbols for ECP;

FIG. 22 illustrates examples of a shifted RS pattern with FDM among UEs for two DMRS in every 7 symbols for NCP;

FIG. 23 illustrates examples of long PUCCH with one DMRS every 7 symbols for NCP;

FIG. 24 illustrates examples of DMRS allocation at frequency domain;

FIG. 25 illustrates examples of UE multiplexing with different DMRS patterns;

FIG. 26 illustrates examples of frequency hopping for long PUCCH formats;

FIG. 27 illustrates examples of self-contained DMRS patterns in each symbol;

FIG. 28 illustrates various components that may be utilized in a UE;

FIG. 29 illustrates various components that may be utilized in a gNB;

FIG. 30 is a block diagram illustrating one implementation of a UE in which systems and methods for a slot structure of a long PUCCH design for 5G NR operations may be implemented;

FIG. 31 is a block diagram illustrating one implementation of a gNB in which systems and methods for a slot structure of a long PUCCH design for 5G NR operations may be implemented;

FIG. 32 is a flow diagram illustrating a method for implementing a slot structure of a long PUCCH design for 5G NR; and

FIG. 33 is a flow diagram illustrating another method for implementing a slot structure of a long PUCCH design for 5G NR.

DETAILED DESCRIPTION

A user equipment (UE) is described. The UE includes a processor and memory in electronic communication with the processor. Instructions stored in the memory are executable to determine an uplink control channel (PUCCH) format and configuration based on a signaling from a base station (gNB). The instructions are also executable to determine demodulation reference signal (DMRS) locations in the configured PUCCH. The instructions are further executable to determine uplink control information (UCI) multiplexing methods on the configured PUCCH. The instructions are additionally executable to determine a resource of a control channel for UCI feedback. The instructions are also executable to transmit UCI feedback on the selected control channel.

Determining the uplink control channel (PUCCH) format and configuration may include a long PUCCH format that supports more than 2 bits of UCI payload. A long PUCCH may employ a format that comprises a waveform, a number of resource blocks (RBs), a reference symbol (RS) pattern, and/or orthogonal sequences on RS and data symbols, and/or one or more control resource regions. RS symbols may be allocated at time domain, and orthogonal sequences may be applied for UCI data at time domain or frequency domain.

The DMRS of a long PUCCH may occupy fixed locations in a slot structure, or are relative to the starting symbol of a long PUCCH. If there is only 1 DMRS in a long PUCCH, frequency hopping may not be supported, and if there are 2 or more DMRS in a long PUCCH, frequency hopping may be mandatory or configurable. If frequency hopping is configured or supported, the hopping location may be fixed based on DMRS structure.

Frequency hopping may be mandatory or configurable, and the DMRS of a long PUCCH may be determined per frequency hop based on basic building blocks. A long PUCCH may include one or two basic building blocks with the same length or a length difference of one, where each basic building block is configured with 1 or 2 DMRS following a pattern in the basic building blocks with lengths of 4-7 symbols. A hopping position may be determined at the middle of a given long PUCCH, and DMRS positions in each hop may be determined based on the length of the hop from the basic building blocks.

A base station (gNB) is also described. The gNB includes a processor and memory in electronic communication with the processor. Instructions stored in the memory are executable to determine an uplink control channel (PUCCH) format and configuration. The instructions are also executable to determine the DMRS locations in the configured PUCCH. The instructions are further executable to determine the UCI multiplexing methods on the configured PUCCH. The instructions are additionally executable to determine the resource of the control channel for UCI feedback. The instructions are also executable to receive UCI feedback on a selected control channel. A control channel used for UCI feedback and a resource of the control channel for UCI feedback are determined based on signaling from the gNB.

The 3rd Generation Partnership Project, also referred to as “3GPP,” is a collaboration agreement that aims to define globally applicable technical specifications and technical reports for third and fourth generation wireless communication systems. The 3GPP may define specifications for next generation mobile networks, systems and devices.

3GPP Long Term Evolution (LTE) is the name given to a project to improve the Universal Mobile Telecommunications System (UMTS) mobile phone or device standard to cope with future requirements. In one aspect, UMTS has been modified to provide support and specification for the Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN).

At least some aspects of the systems and methods disclosed herein may be described in relation to the 3GPP LTE, LTE-Advanced (LTE-A) and other standards (e.g., 3GPP Releases 8, 9, 10, 11 and/or 12). However, the scope of the present disclosure should not be limited in this regard. At least some aspects of the systems and methods disclosed herein may be utilized in other types of wireless communication systems.

A wireless communication device may be an electronic device used to communicate voice and/or data to a base station, which in turn may communicate with a network of devices (e.g., public switched telephone network (PSTN), the Internet, etc.). In describing systems and methods herein, a wireless communication device may alternatively be referred to as a mobile station, a UE, an access terminal, a subscriber station, a mobile terminal, a remote station, a user terminal, a terminal, a subscriber unit, a mobile device, etc. Examples of wireless communication devices include cellular phones, smart phones, personal digital assistants (PDAs), laptop computers, netbooks, e-readers, wireless modems, etc. In 3GPP specifications, a wireless communication device is typically referred to as a UE. However, as the scope of the present disclosure should not be limited to the 3GPP standards, the terms “UE” and “wireless communication device” may be used interchangeably herein to mean the more general term “wireless communication device.” A UE may also be more generally referred to as a terminal device.

In 3GPP specifications, a base station is typically referred to as a Node B, an evolved Node B (eNB), a home enhanced or evolved Node B (HeNB) or some other similar terminology. As the scope of the disclosure should not be limited to 3GPP standards, the terms “base station,” “Node B,” “eNB,” and “HeNB” may be used interchangeably herein to mean the more general term “base station.” Furthermore, the term “base station” may be used to denote an access point. An access point may be an electronic device that provides access to a network (e.g., Local Area Network (LAN), the Internet, etc.) for wireless communication devices. The term “communication device” may be used to denote both a wireless communication device and/or a base station. An eNB may also be more generally referred to as a base station device.

It should be noted that as used herein, a “cell” may be any communication channel that is specified by standardization or regulatory bodies to be used for International Mobile Telecommunications-Advanced (IMT-Advanced) and all of it or a subset of it may be adopted by 3GPP as licensed bands (e.g., frequency bands) to be used for communication between an eNB and a UE. It should also be noted that in E-UTRA and E-UTRAN overall description, as used herein, a “cell” may be defined as “combination of downlink and optionally uplink resources.” The linking between the carrier frequency of the downlink resources and the carrier frequency of the uplink resources may be indicated in the system information transmitted on the downlink resources.

“Configured cells” are those cells of which the UE is aware and is allowed by an eNB to transmit or receive information. “Configured cell(s)” may be serving cell(s). The UE may receive system information and perform the required measurements on all configured cells. “Configured cell(s)” for a radio connection may consist of a primary cell and/or no, one, or more secondary cell(s). “Activated cells” are those configured cells on which the UE is transmitting and receiving. That is, activated cells are those cells for which the UE monitors the physical downlink control channel (PDCCH) and in the case of a downlink transmission, those cells for which the UE decodes a physical downlink shared channel (PDSCH). “Deactivated cells” are those configured cells that the UE is not monitoring the transmission PDCCH. It should be noted that a “cell” may be described in terms of differing dimensions. For example, a “cell” may have temporal, spatial (e.g., geographical) and frequency characteristics.

Fifth generation (5G) cellular communications (also referred to as “New Radio”, “New Radio Access Technology” or “NR” by 3GPP) envisions the use of time/frequency/space resources to allow for enhanced mobile broadband (eMBB) communication and ultra-reliable low latency communication (URLLC) services, as well as massive machine type communication (mMTC) like services. In order for the services to use the time/frequency/space medium efficiently it would be useful to be able to flexibly schedule services on the medium so that the medium may be used as effectively as possible, given the conflicting needs of URLLC, eMBB, and mMTC. A new radio base station may be referred to as a gNB. A gNB may also be more generally referred to as a base station device.

In 5G NR, at least two different types of uplink control channel (PUCCH) formats may be specified: at least one short PUCCH format and one long PUCCH format. The PUCCH channel is designed to carry uplink control information (UCI). In NR, the long PUCCH format may span over multiple slots, and the PUCCH format of a UE may be configured by a base station. The systems and methods described herein detail formats for long PUCCH design. In particular, the RS patterns, the RS location and configurations for a long PUCCH are described herein. The demodulation reference signal (DMRS) pattern described herein focuses on a long PUCCH within a slot structure.

In NR, several PUCCH formats will be specified. For UCI, different UCI may be reported on different PUCCH channel formats. In 5G NR, both CP-OFDM and DFT-S-OFDM waveforms are supported for UL transmission. Also, different numerologies may be used on one or more carriers or serving cells.

Detailed mapping methods and signaling required for long PUCCH formats in NR are described. To minimize specification impact, a common framework may be used for both CP-OFDM and DFT-S-OFDM based long PUCCH design. Furthermore, design enhancements for some band-specific and application-specific scenarios are described.

For a long PUCCH within a slot length, the DMRS may be determined based on the length of a long PUCCH, the frequency hopping requirements, etc. In one method, the DMRSs in a long PUCCH are in fixed locations in a slot configured by higher layer signaling. In another method, the DMRSs in a long PUCCH are in fixed locations in a long PUCCH relative to the starting symbol position.

In these two methods, frequency hopping may not be supported if there is only one DMRS in the long PUCCH duration. If there are more than 2 DMRSs in the long PUCCH duration, frequency hopping can be supported. If supported, frequency hopping may be mandatory or configured by higher layer signaling. However, these methods may not provide the best DMRS positions for a long PUCCH depending on the starting and ending symbols of a long PUCCH.

In another method, the DMRSs are determined based on the structure of each frequency hop. Frequency hopping may be mandatory for all long PUCCH durations, or it can be configured by higher layer signaling based on a long PUCCH duration.

Furthermore, to allow more flexible UE multiplexing and UCI payload sizes, the UE multiplexing capability may be supported at frequency domain instead of time domain.

Various examples of the systems and methods disclosed herein are now described with reference to the Figures, where like reference numbers may indicate functionally similar elements. The systems and methods as generally described and illustrated in the Figures herein could be arranged and designed in a wide variety of different implementations. Thus, the following more detailed description of several implementations, as represented in the Figures, is not intended to limit scope, as claimed, but is merely representative of the systems and methods.

FIG. 1 is a block diagram illustrating one implementation of one or more gNBs 160 and one or more UEs 102 in which systems and methods for a slot structure of a long physical uplink control channel (PUCCH) design for 5th generation (5G) new radio (NR) may be implemented. The one or more UEs 102 communicate with one or more gNBs 160 using one or more antennas 122 a-n. For example, a UE 102 transmits electromagnetic signals to the gNB 160 and receives electromagnetic signals from the gNB 160 using the one or more antennas 122 a-n. The gNB 160 communicates with the UE 102 using one or more antennas 180 a-n.

The UE 102 and the gNB 160 may use one or more channels 119, 121 to communicate with each other. For example, a UE 102 may transmit information or data to the gNB 160 using one or more uplink channels 121. Examples of uplink channels 121 include a PUCCH and a PUSCH, etc. The one or more gNBs 160 may also transmit information or data to the one or more UEs 102 using one or more downlink channels 119, for instance. Examples of downlink channels 119 include a PDCCH, a PDSCH, etc. Other kinds of channels may be used.

Each of the one or more UEs 102 may include one or more transceivers 118, one or more demodulators 114, one or more decoders 108, one or more encoders 150, one or more modulators 154, a data buffer 104 and a UE operations module 124. For example, one or more reception and/or transmission paths may be implemented in the UE 102. For convenience, only a single transceiver 118, decoder 108, demodulator 114, encoder 150 and modulator 154 are illustrated in the UE 102, though multiple parallel elements (e.g., transceivers 118, decoders 108, demodulators 114, encoders 150 and modulators 154) may be implemented.

The transceiver 118 may include one or more receivers 120 and one or more transmitters 158. The one or more receivers 120 may receive signals from the gNB 160 using one or more antennas 122 a-n. For example, the receiver 120 may receive and downconvert signals to produce one or more received signals 116. The one or more received signals 116 may be provided to a demodulator 114. The one or more transmitters 158 may transmit signals to the gNB 160 using one or more antennas 122 a-n. For example, the one or more transmitters 158 may upconvert and transmit one or more modulated signals 156.

The demodulator 114 may demodulate the one or more received signals 116 to produce one or more demodulated signals 112. The one or more demodulated signals 112 may be provided to the decoder 108. The UE 102 may use the decoder 108 to decode signals. The decoder 108 may produce decoded signals 110, which may include a UE-decoded signal 106 (also referred to as a first UE-decoded signal 106). For example, the first UE-decoded signal 106 may comprise received payload data, which may be stored in a data buffer 104. Another signal included in the decoded signals 110 (also referred to as a second UE-decoded signal 110) may comprise overhead data and/or control data. For example, the second UE-decoded signal 110 may provide data that may be used by the UE operations module 124 to perform one or more operations.

In general, the UE operations module 124 may enable the UE 102 to communicate with the one or more gNBs 160. The UE operations module 124 may include one or more of a UE long PUCCH module 126.

The UE long PUCCH module 126 may implement a long PUCCH design for 5th generation (5G) new radio (NR). Uplink control information and uplink waveform in NR are described. In LTE, the UCI carries hybrid-ARQ acknowledgements (HARQ-ACK), channel state information (CSI), and a scheduling request (SR). The CSI may include one or more of channel quality indicator (CQI), rank indication (RI), precoding matrix indicator (PMI), precoding type indicator (PTI), etc. Multiple dimensions of CSI may be reported from one or more cells to support FD-MIMO and CoMP operations.

Similarly, in NR, a scheduling request (SR), if defined, needs to be transmitted outside PUSCH, as well as HARQ-ACK for latency reasons. The CSI report in NR should be enhanced to support massive MIMO and beamforming methods. Thus, multiple sets of CSI may be reported in NR. Again, a CSI feedback may include one or more of CQI, RI, PMI, PTI, beam index, etc. At least two types of CSI reports may be supported, periodic CSI and aperiodic CSI. Periodic CSI report can be configured semi-statically. Aperiodic CSI can be trigger with a CSI request from the gNB 160. Therefore, physical uplink control signaling should be able to carry at least hybrid-ARQ acknowledgements, CSI reports (possibly including beamforming information), and scheduling requests.

The UCI information may be transmitted as L1/L2 control signaling (e.g., via a physical uplink control channel (PUCCH) or physical uplink share channel (PUSCH) or uplink data channel). Furthermore, it should be possible to dynamically indicate (at least in combination with radio resource control (RRC)) the timing between data reception and hybrid-ARQ acknowledgement transmission as part of the downlink control information (DCI).

In NR, different numerologies are supported on the same or different carriers. For the uplink transmission supports two waveform/modulation schemes based on Orthogonal Frequency Division Multiplexing (OFDM). One waveform/modulation scheme is cyclic prefix OFDM (CP-OFDM). Another waveform/modulation scheme is discrete Fourier transform (DFT) spread OFDM (DFT-S-OFDM), also known as single carrier FDMA (SC-FDMA), or low Peak-to-Average Power Ratio (PAPR) waveform. Therefore, the uplink control and uplink data channel may be configured separately with the same or different waveforms and numerologies.

NR numerology and slot length is described herein. Multiple OFDM numerologies are supported, as given by Table 1.

TABLE 1 μ Δf = 2^(μ) · 15[kHz] Cyclic prefix 0 15 Normal 1 30 Normal 2 60 Normal, Extended 3 120 Normal 4 240 Normal 5 480 Normal

For subcarrier spacing configuration μ, slots are numbered

n_(s)^(μ) ∈ {0, K, N_(subframe)^(slots, μ) − 1} in increasing order within a subframe and

n_(s, f)^(μ) ∈ {0, K, N_(frame)^(slots, μ) − 1} in increasing order within a frame. There are N_(symb) ^(μ) consecutive OFDM symbols in a slot where N_(symb) ^(μ) depends on the subcarrier spacing used and the slot configuration as given by Table 2 and Table 3. The start of slot n_(s) ^(μ) in a subframe is aligned in time with the start of OFDM symbol n_(s) ^(μ) N_(symb) ^(μ) in the same subframe.

Not all UEs 102 may be capable of simultaneous transmission and reception, implying that not all OFDM symbols in a downlink slot or an uplink slot may be used.

Table 2 shows the number of OFDM symbols per slot, N_(symb) ^(μ), for subcarrier spacing configuration μ and normal cyclic prefix.

TABLE 2 Slot configuration 0 1 μ N_(symb) ^(μ) N_(frame) ^(slots,μ) N_(subframe) ^(slots,μ) N_(symb) ^(μ) N_(frame) ^(slots,μ) N_(subframe) ^(slots,μ) 0 14 10 1 7 20 2 1 14 20 2 7 40 4 2 14 40 4 7 80 8 3 14 80 8 — — — 4 14 160 16 — — — 5 14 320 32 — — —

Table 3 shows the number of OFDM symbols per slot, N_(symb) ^(μ), for subcarrier spacing configuration μ and extended cyclic prefix.

TABLE 3 Slot configuration 0 1 μ N_(symb) ^(μ) N_(frame) ^(slots,μ) N_(subframe) ^(slots,μ) N_(symb) ^(μ) N_(frame) ^(slots,μ) N_(subframe) ^(slots,μ) 2 12 40 4 6 80 8

LTE and 5G NR physical uplink control channel (PUCCH) are also discussed herein. In LTE, the PUCCH with normal TTI length occupies a full subframe and 1 resource block (RB) for format 1/2/3/5, and more than one RB is supported for Format 4. Different formats are used to carry different number of UCI payload sizes. Frequency hopping is supported for all 1 ms TTI PUCCH formats by transmitting two slots in two ends of the carrier frequency. The UE multiplexing capability is performed in the frequency domain and/or time domain depending on the PUCCH format.

Format 1/1a/1b has 3 RS symbols in each slot. Zadoff-Chu (Z-C) sequence is used on frequency domain, orthogonal sequences are used for PUCCH spreading in time domain, N_(SF) ^(PUCCH)=4 for normal CP, N_(SF) ^(PUCCH)=3 for extended CP.

Format 2/2a/2b has two RS symbols in each slot. It uses Z-C sequences on frequency domain for UE multiplexing, no time domain multiplexing.

Format 3 has two RS symbols in each slot, it only uses time domain multiplexing with orthogonal sequences (N_(SF) ^(PUCCH)=5 for normal CP and N_(SF) ^(PUCCH)=4 for extended CP) and no frequency domain multiplexing.

Format 4 may occupy one or more RBs. It carries coded information bits on all data carrying symbols. Thus, it provides largest payload size, but does not support multiplexing for multiple UEs 102 in the same RB.

Format 5 uses only one RB, It has the same structure as Format 4 except that a spreading factor of 2 N_(SF) ^(PUCCH)=2 is supported, thus two UEs 102 can be multiplexed on the same RB resources.

Similar to different PUCCH formats in LTE, at least two transmission durations are supported for uplink control in NR. One short transmission duration around the last OFDM symbol in a slot may be supported for uplink control in NR. This short transmission duration may be time division multiplexed (TDM) or frequency division multiplexed (FDM) with data. One long transmission duration spanning multiple symbols (e.g. filling most of a slot or slots) may be frequency division multiplexed (FDM) with data.

A short PUCCH format may consist of one or two symbols. A long PUCCH format may span multiple symbols and slots. Multiple long PUCCH formats may be defined (e.g., 4 symbols, a slot, and multiple slots, etc.). A long PUCCH format may be useful for larger payload HARQ-ACK feedback, CSI feedback, etc.

At least a low PAPR/CM design should be supported for the long PUCCH format. A UCI carried by long duration UL control channel at least with low PAPR design can be transmitted in one slot or multiple slots, and transmission across multiple slots should allow a total duration of 1 ms at least for some cases.

At least one or more of the following PUCCH formats may be supported. PUCCH format 1 may be a short PUCCH. In PUCCH format 1, transmission is over 1 symbol or 2 symbols, and the number of UCI (e.g., HARQ-ACK) bits may be 1 or 2.

PUCCH format 2 may be a short PUCCH. In PUCCH format 2, transmission is over 1 symbol or 2 symbols, and the number of UCI (e.g., HARQ-ACK) bits may be more than 2.

PUCCH format 3 may be a long PUCCH. In PUCCH format 3, transmission is over 4 or more symbols and the number of UCI (e.g., HARQ-ACK) bits may be 1 or 2.

PUCCH format 4 may be a long PUCCH. In PUCCH format 4, transmission is over 4 or more symbols, and the number of UCI (e.g., HARQ-ACK) bits may be more than 2.

A UE 102 may transmit one or more PUCCHs within a period of L_(PUCCH) symbols, referred to as PUCCH slot. Either L_(PUCCH)=7 or L_(PUCCH)=14 may be supported, where one value is configured by higher layers. If the UE 102 detects a DCI format in a PDCCH that configures a PDSCH reception over a number of symbols with a last symbol being within PUCCH slot n, the UE 102 may provide corresponding HARQ-ACK information in a PUCCH transmission within PUCCH slot n+k, where k is indicated by the DCI format.

For PUCCH format configuration, a combination of semi-static configuration and (at least for some types of UCI information) dynamic signaling is used to determine the PUCCH formats and resources both for the long and short PUCCH formats.

The long PUCCH design for 5G NR is described more fully herein. Long PUCCH design with more than 2 bits of UCI payload (i.e., PUCCH format 4) in 5G NR is described. Hereafter, a long PUCCH refers to PUCCH format 4 (i.e., a PUCCH with a length of 4 or more symbols) and the number of UCI (e.g., HARQ-ACK) bits is more than 2. FIG. 13 shows several examples of long PUCCH duration design.

In one case, a long PUCCH should occupy one or more whole slots. In FIG. 13, example (a) shows a long PUCCH covers a full slot length in a UL only slot. In FIG. 13, example (b) shows a long PUCCH covers multiple UL only slots. In this case, a long PUCCH should not be configured in partial UL slots (e.g., in a self-contained slot or UL centric slot). Otherwise, a different PUCCH structure may be defined for an UL centric slot with a different number of symbols. For example, the RS location, RS and UCI multiplexing methods, the orthogonal sequences used for UE multiplexing, etc.

In another case, a long PUCCH can be designed for one or more slots, but some symbols may be punctured in a UL centric slot. In this case, the design should take into account of potential puncturing of some symbols up to a given limit (e.g., 4 symbols).

In yet another case, a long PUCCH may be configured in the UL part of a slot with the number of uplink symbols greater than a threshold number X. However, different designs on the DMRS and orthogonal sequences for UE multiplexing may be used for a different number of symbols in a long PUCCH.

The X value may be 4 as agreed in 3GPP meetings. In NR, a slot may be configured as 7 symbols or 10 symbols. Therefore, for normal CP, if a slot includes 7 symbols, a long PUCCH in a slot may have durations from 4 to 7 symbols. If a slot includes 14 symbols, a long PUCCH in a slot may have durations from 4 to 14 symbols. Similarly, for extended CP, if a slot includes 6 symbols, a long PUCCH in a slot may have durations from 4 to 6 symbols. If a slot includes 12 symbols, a long PUCCH in a slot may have durations from 4 to 12 symbols.

A long PUCCH may occupy all UL symbols in a UL centric slot, as shown in example (c) of FIG. 13. Alternatively, a long PUCCH may occupy part of the UL symbols to the end of a UL centric slot or a UL only slot, as shown in example (e) of FIG. 13.

A long PUCCH may occupy some symbols in a UL centric or a UL only slot, as shown in Figure (g) of FIG. 13. In this case, a long PUCCH may start from the beginning of or the middle of a UL only slot or the staring UL symbol of a UL centric slot, and may end in the middle of or at the end of a UL only slot or the staring UL symbol of a UL centric slot, as long as the number of symbols is greater or equal to a threshold X.

In the case where a long PUCCH spans over multiple slots, it is possible that a long PUCCH spans over both UL centric slot and UL only slots. The UE multiplexing capability may be different for the UL centric slot and the UL only slot due to a different number of symbols available for symbol multiplexing.

In one approach, a long PUCCH should always be configured to the end of a UL centric or UL only slot, as shown in example (d) and example (f) of FIG. 13. In another approach, a long PUCCH may start from a UL symbol in a UL centric or UL only slot, and ends in a symbol in the same slot or a consecutive UL slot, as shown in example (h) of FIG. 13.

As a summary for long PUCCH duration, a long PUCCH may occupy part of the symbols of a UL centric or UL only slot. A long PUCCH may occupy all symbols of a UL centric or UL only slot. A long PUCCH may occupy part of the symbols of a UL centric or UL only slot followed by one or more consecutive UL only slots.

From a design perspective, options in examples (a), (b), (c) and (d) of FIG. 13 may be more consistent because the long PUCCH always occupies all symbols of UL centric or UL only slots. On the other hand, the other options may provide more flexibility for PUCCH resource assignment.

The long PUCCH may support both DFT-S-OFDM and CP-OFDM based formats. In the following sections, the long PUCCH design for different waveforms in a UL centric and a UL only slot is discussed. First, the PUCCH structure in a UL only slot will be discussed first, followed by the UL centric slot considerations.

Regarding a DFT-S-OFDM-based long PUCCH, long PUCCH formats should support at least for low PAPR waveform (i.e., DFT-S-OFDM). For DFT-S-OFDM based long PUCCH formats, the LTE PUCCH structure may be reused in NR, at least on the DMRS location and spreading sequence design. Thus, the following two DMRS patterns should be supported for NR long PUCCH with low PAPR or DFT-S-OFDM waveform.

A first DMRS pattern (Pattern 1) includes 2 RS in every 7 or 6 symbols, as shown in FIG. 14. With this pattern, a long PUCCH format has 2 DMRS in every 7 symbols for normal CP (NCP), and 2 DMRS in every 6 symbols for extended CP (ECP) within a slot, as shown in FIG. 14 with the DMRS positions.

The DMRS signal generation and spreading sequences for UCI data can be the same as in LTE PUCCH format 2 and PUCCH Format 3. Therefore, at least two formats can be supported for NR long PUCCH format depending on the UCI data spreading methods. In one format, within each RB, different UCI symbols are transmitted on different OFDM symbols, and spreading factor is applied at frequency domain with the Z-C sequence. This is similar to LTE PUCCH Format 2.

In another format, within each RB, different UCI symbols are transmitted on different subcarriers, and spreading factor is applied at time domain with the orthogonal sequences given in Table 4 below, where N_(SF) ^(PUCCH)=5 or normal CP and N_(SF) ^(PUCCH)=4 for extended CP. This is similar to LTE PUCCH Format 3. Table 4 provides an orthogonal sequence w_(n) _(oc) (i)

TABLE 4 Sequence Orthogonal sequence [w_(n) _(oc) (0) Λ w_(n) _(oc) (N_(SF) ^(PUCCH) − 1)] index n_(oc) N_(SF) ^(PUCCH) = 5 N_(SF) ^(PUCCH) = 4 0 [1 1 1 1 1] [+1 +1 +1 +1] 1 [1 e^(j2π/5) e^(j4π/5) e^(j6π/5) e^(j8π/5)] [+1 −1 +1 −1] 2 [1 e^(j4π/5) e^(j8π/5) e^(j2π/5) e^(j6π/5)] [+1 +1 −1 −1] 3 [1 e^(j6π/5) e^(j2π/5) e^(j8π/5) e^(j4π/5)] [+1 −1 −1 +1] 4 [1 e^(j8π/5) e^(j6π/5) e^(j4π/5) e^(j2π/5)] —

The pattern above assumes all symbols in a UL only slot is used. In a case where some or all symbols of a UL centric slot or a part of UL symbols in a UL only slot can be used for a long PUCCH, a long PUCCH design may reuse the DMRS pattern for all symbols of a UL only slot. That is, the DMRS location in a slot may be fixed regardless of the duration of a long PUCCH. This provides better RS multiplexing capabilities and avoids interference from UCI from other PUCCH transmissions.

Therefore, if a long PUCCH always occupy the UL symbols to the end of a UL centric or a UL only slot, the minimum number of symbols X should be 3 for a long PUCCH in a UL centric slot or UL only slot to ensure a DMRS symbol included in a long PUCCH, as shown in FIG. 15(a). If a long PUCCH can be allocated with any set of symbols in a slot, the minimum number of symbols X may be 4 for normal CP to ensure a DMRS symbol included in a long PUCCH, as shown in FIG. 15(b).

In the following discussion, as a general example, the long PUCCH may be assumed to always occupy the UL symbols to the end of a UL centric or a UL only slot. In one format, within each RB, different UCI symbols are transmitted on different OFDM symbols, and spreading factor is applied at frequency domain with the Z-C sequence. This is similar to LTE PUCCH Format 2. The same structure can be used in a long PUCCH occupying all symbols or some symbols of a UL centric slot or some symbols of a UL only slot. This results in a reduced number of UCI carrying symbols compared with a long PUCCH occupying all symbols of a UL only slot.

Also in this format, the frequency domain multiplexing may apply a length 12 orthogonal covering code in each RB instead of a Z-C sequence. This allows multiple UCI symbols to be carried on different subcarriers. Several examples of length 12 OCC codes are as follows.

For 2 UE multiplexing, the OCC in frequency domain can be as given in Table 5. Each UE 102 may carry 6 QPSK UCI symbols in each RB of a UCI carrying symbol.

TABLE 5 Sequence Orthogonal sequence [w_(n) _(CDM) (0) Λ w_(n) _(CDM) (N_(SC) ^(RB) − 1)] index n_(oc) N_(SF) ^(PUCCH) = 2 0 [1 1 1 1 1 1 1 1 1 1 1 1] 1 [1 −1 1 −1 1 −1 1 −1 1 −1 1 −1]

For 3 UE multiplexing, the OCC in frequency domain can be as given in Table 6. Each UE 102 may carry 4 QPSK UCI symbols in each RB of a UCI carrying symbol.

TABLE 6 Sequence Orthogonal sequence [w_(n) _(CDM) (0) Λ w_(n) _(CDM) (N_(SC) ^(RB) − 1)] index n_(oc) N_(SF) ^(PUCCH) = 3 0 [1 1 1 1 1 1 1 1 1 1 1 1] 1 [1 e^(j2π/3) e^(j4π/3) 1 e^(j2π/3) e^(j4π/3) 1 e^(j2π/3) e^(j4π/3) 1 e^(j2π/3) e^(j4π/3)] 2 [1 e^(j4π/3) e^(j2π/3) 1 e^(j4π/3) e^(j2π/3) 1 e^(j4π/3) e^(j2π/3) 1 e^(j4π/3) e^(j2π/3)]

For 4 UE multiplexing, the OCC in frequency domain can be given as given in Table 7. Each UE 102 may carry 3 QPSK UCI symbols in each RB of a UCI carrying symbol.

TABLE 7 Sequence Orthogonal sequence [w_(n) _(CDM) (0) Λ w_(n) _(CDM) (N_(SC) ^(RB) − 1)] index n_(oc) N_(SF) ^(PUCCH) = 4 0 [1 1 1 1 1 1 1 1 1 1 1 1] 1 [+1 −1 +1 −1 +1 −1 +1 −1 +1 −1 +1 −1] 2 [+1 +1 −1 −1 +1 +1 −1 −1 +1 +1 −1 −1] 3 [+1 −1 −1 +1 +1 −1 −1 +1 +1 −1 −1 +1]

With frequency OCC, the same OCC can be applied to all UCI carrying symbols. Thus, the total number of UCI symbols can be determined based the number of UCI carrying.

In another format, within each RB, different UCI symbols are transmitted on different subcarriers, and spreading factor is applied at time domain with the orthogonal sequences since a long PUCCH occupying part of a slot in a UL centric slot or UL only slot may have different number of UL symbols.

If the number of symbols is 3 for the long PUCCH, one symbol is used as DMRS, only 2 symbols are used for UCI UE multiplexing, the number of orthogonal sequences can only be 2. Table 8 provides an orthogonal sequence w_(n) _(oc) (i) for a 3-symbol long PUCCH.

TABLE 8 Sequence Orthogonal sequence [w_(n) _(oc) (0) Λ w_(n) _(oc) (N_(SF) ^(PUCCH) − 1)] index n_(oc) N_(SF) ^(PUCCH) = 2 0 [+1 +1] 1 [+1 −1]

If the number of symbols is 4 for the long PUCCH, 1 symbol is used as DMRS, only 3 symbols are used for UCI UE multiplexing, the number of orthogonal sequences can only be 3. Table 9 provides an orthogonal sequence w_(n) _(oc) (i) for a 4-symbol long PUCCH.

TABLE 9 Sequence Orthogonal sequence [w_(n) _(oc) (0) Λ w_(n) _(oc) (N_(SF) ^(PUCCH) − 1)] index n_(oc) N_(SF) ^(PUCCH) = 3 0 [1 1 1] 1 [1 e^(j2π/3) e^(j4π/3)] 2 [1 e^(j4π/3) e^(j2π/3)]

If the number of symbols is 5 for the long PUCCH, for normal CP, 1 symbol is used as DMRS, and 4 symbols are used for UCI UE multiplexing, the number of orthogonal sequences can only be 4. Table 10 provides an orthogonal sequence w_(n) _(oc) (i) for a 5-symbol long PUCCH with normal CP.

TABLE 10 Sequence Orthogonal sequence [w_(n) _(oc) (0) Λ w_(n) _(oc) (N_(SF) ^(PUCCH) − 1)] index n_(oc) N_(SF) ^(PUCCH) = 4 0 [+1 +1 +1 +1] 1 [+1 −1 +1 −1] 2 [+1 +1 −1 −1] 3 [+1 −1 −1 +1]

If the number of symbols is 5 for the long PUCCH, for extended CP, 2 symbols are used as DMRS, and 3 symbols are used for UCI UE multiplexing, the number of orthogonal sequences can only be 3. The same orthogonal sequences as for 4 symbols long PUCCH can be used. Table 11 provides an orthogonal sequence w_(n) _(oc) (i) for a 5-symbol long PUCCH with extended CP.

TABLE 11 Sequence Orthogonal sequence [w_(n) _(oc) (0) Λ w_(n) _(oc) (N_(SF) ^(PUCCH) − 1)] index n_(oc) N_(SF) ^(PUCCH) = 3 0 [1 1 1] 1 [1 e^(j2π/3) e^(j4π/3)] 2 [1 e^(j4π/3) e^(j2π/3)]

If the number of symbols is 6 for the long PUCCH, for normal CP, 2 symbols are used as DMRS, and 4 symbols are used for UCI UE multiplexing, the number of orthogonal sequences can only be 4. The same orthogonal sequences as for 5 symbols long PUCCH can be used. Table 12 provides an orthogonal sequence w_(n) _(oc) (i) for a 5-symbol long PUCCH with normal CP.

TABLE 12 Sequence Orthogonal sequence [w_(n) _(oc) (0) Λ w_(n) _(oc) (N_(SF) ^(PUCCH) − 1)] index n_(oc) N_(SF) ^(PUCCH) = 4 0 [+1 +1 +1 +1] 1 [+1 −1 +1 −1] 2 [+1 +1 −1 −1] 3 [+1 −1 −1 +1]

If a slot has 14 symbols, and a long PUCCH is configured with more than 7 symbols, the above mentioned constrains can be applied for every 7 symbols, and the UE multiplexing capability may be limited by the UL portion that is smaller than 7 symbols. And the UE 102 may be configured with an orthogonal sequence for the 7-symbol part and another orthogonal sequence for portion that is smaller than 7 symbols. In this case, only a subset of orthogonal sequences on a 7 symbol part can be configured for a UE 102.

Similarly, if a long PUCCH includes both UL centric and UL only slots, the UE multiplexing capability may be limited by the UL centric slot as described above. Thus, in this case, only a subset of orthogonal sequences on a UL only slot can be configured for a UE 102. And the UE 102 may be configured with an orthogonal sequence for the UL centric part and another orthogonal sequence for the UL only parts. With this method, the UCI payload is not reduced in the UL centric and UL only slot.

In another method, if a slot has 14 symbols, and a long PUCCH is configured with more than 7 symbols, the orthogonal sequences for UE multiplexing can be jointly designed across all configured symbols for the long PUCCH in the slot. Similarly, if a long PUCCH includes both UL centric and UL only slots, the orthogonal sequences for UE multiplexing can be jointly designed across the UL centric and UL only slot. For example, if a UL-centric slot has 3 UCI carrying symbols, and a UL only slot has 5 UCI carrying symbols, eight orthogonal sequences of length eight can be generated for UE multiplexing. In this case, the UE multiplexing capability is increased, but the UCI payload is reduced across all symbols, or across the UL centric and UL only slots.

A second DMRS pattern (Pattern 2) includes one RS in every 7 or 6 symbols, as shown in FIG. 16. With this pattern, a long PUCCH format has 1 DMRS in every 7 symbols for normal CP (NCP), and 1 DMRS in every 6 symbols for extended CP (ECP) within a slot, as shown in FIG. 16 with the DMRS positions.

The DMRS signal generation and spreading sequences for UCI data can be similar to LTE PUCCH format 4 if no UE multiplexing in the same RB is supported. If up to 2 UE multiplexing is supported in the same RB, an orthogonal sequence in Table 13 with spreading factor of 2 can be used, which is similar to PUCCH format 5.

TABLE 13 n_(oc) Orthogonal sequences [w_(n) _(CDM) (0) Λ w_(n) _(CDM) (N_(SC) ^(RB) − 1)] 0 [+1 +1 +1 +1 +1 +1 +1 +1 +1 +1 +1 +1] 1 [+1 +1 +1 +1 +1 +1 −1 −1 −1 −1 −1 −1]

The pattern above assumes all symbols in a UL only slot is used. In a case where some or all symbols of a UL centric slot, or a part of UL symbols in a UL only slot can be used for a long PUCCH, for a long PUCCH design should reuse the DMRS pattern for UL only slot.

Similarly, other length 12 OCC codes can be applied to allow multiple UCI symbols to be carried on different subcarriers. For example, for 3 UE multiplexing, the OCC in frequency domain can be as given in Table 14. Each UE 102 may carry 4 QPSK UCI symbols in each RB of a UCI carrying symbol.

TABLE 14 Sequence Orthogonal sequence [w_(n) _(CDM) (0) Λ w_(n) _(CDM) (N_(SC) ^(RB) − 1)] index n_(oc) N_(SF) ^(PUCCH) = 3 0 [1 1 1 1 1 1 1 1 1 1 1 1] 1 [1 e^(j2π/3) e^(j4π/3) 1 e^(j2π/3) e^(j4π/3) 1 e^(j2π/3) e^(j4π/3) 1 e^(j2π/3) e^(j4π/3)] 2 [1 e^(j4π/3) e^(j2π/3) 1 e^(j4π/3) e^(j2π/3) 1 e^(j4π/3) e^(j2π/3) 1 e^(j4π/3) e^(j2π/3)]

For 4 UE multiplexing, the OCC in frequency domain can be given as given in Table 15. Each UE 102 may carry 3 QPSK UCI symbols in each RB of a UCI carrying symbol.

TABLE 15 Sequence Orthogonal sequence [w_(n) _(CDM) (0) Λ w_(n) _(CDM) (N_(SC) ^(RB) − 1)] index n_(oc) N_(SF) ^(PUCCH) = 4 0 [1 1 1 1 1 1 1 1 1 1 1 1] 1 [+1 −1 +1 −1 +1 −1 +1 −1 +1 −1 +1 −1] 2 [+1 +1 −1 −1 +1 +1 −1 −1 +1 +1 −1 −1] 3 [+1 −1 −1 +1 +1 −1 −1 +1 +1 −1 −1 +1]

With frequency OCC, the same OCC can be applied to all UCI carrying symbols. Thus, the total number of UCI symbols can be determined based the number of UCI carrying.

Therefore, the minimum number of symbols X should be 4 for a long PUCCH in a UL centric slot or UL only slot to ensure a DMRS symbol included in a long PUCCH. If two UEs 102 are multiplexed in the same RB resource, the same orthogonal sequences can be applied on each UCI carrying symbol.

DMRS patterns and frequency hopping are also described herein. Frequency hopping is a key feature for PUCCH to provide frequency diversity. If configured, the PUCCH symbols can be transmitted at different PUCCH regions. For a long PUCCH duration in a slot, only 1 hop is supported. Whether frequency hopping can be supported or not may be determined by the DMRS patterns, and vice versa. The following discussion for frequency hopping and DMRS locations may be applicable to both DFT-S-OFDM based PUCCH and CP-OFDM based PUCCH.

In one method, fixed DMRS pattern in a slot as discussed above can be applied to any long PUCCH duration in a slot, regardless of the starting and ending symbol within the slot. This provides better DMRS alignment among long PUCCHs with different durations.

In another method, a fixed DMRS pattern as discussed above can be applied from the starting symbol on any long PUCCH durations. Thus, the fixed pattern is corresponding to the starting symbol of a long PUCCH instead of the beginning of a slot.

In both cases, the fixed DMRS patterns may result in non-optimal DMRS locations in a PUCCH. Furthermore, frequency hopping may not be possible in some cases if there is only one DMRS present in a given PUCCH duration. Therefore, with fixed DMRS locations in a slot, frequency hopping may not be supported for all PUCCH durations. For example, if there are 2 DMRSs in every 7 symbols with normal CP, a length 4 long PUCCH can only have one DMRS included, thus frequency hopping cannot be applied. Depending on the starting symbol location, there are cases with only one DMRS for long PUCCH durations of 5 or 6 symbols.

Therefore, with fixed DMRS patterns relative to a slot boundary or the starting symbol of a long PUCCH, frequency hopping may be disabled if there is only 1 DMRS in the long PUCCH duration. If there are 2 or more DMRSs in the long PUCCH duration within a slot, in one approach, frequency hopping may be mandatory; in another approach, whether frequency hopping is applied may be configured by higher layer signaling.

With fixed DMRS patterns relative to a slot boundary or the starting symbol of a long PUCCH, the frequency hopping location may also be fixed based on the DMRS patterns. FIG. 17 below shows an example of potential frequency hopping locations.

In yet another method, the DMRS location is determined in each hop based on basic structures of building blocks of different length. Since the long PUCCH duration in a slot may vary between 4-14 symbols, if frequency hopping is applied, each hop may have 2 to 7 symbols. The basic structures of building blocks for each hop are given in FIG. 18. FIGS. 19A and 19B show some examples of DMRS patterns and frequency hopping locations for different long PUCCH durations

CP-OFDM based long PUCCH is also described herein. To minimize the specification impact, a common framework can be used for both DFT-S-OFDM and CP-OFDM-based long PUCCH. Thus, at least the same UCI multiplexing methods as in DFT-S-OFDM-based long PUCCH can be applied for CP-OFDM-based long PUCCH. Furthermore, the RS symbol location can also be maintained the same as in DFT-S-OFDM-based PUCCH.

In DFT-S-OFDM based transmissions, the RS is separated by different Z-C sequences. In CP-OFDM based long PUCCH, the RS should be separated by FDM for different UEs 102. Thus, different UEs 102 are assigned with different RS patterns that are not overlapping with other UEs 102. FIG. 20 and FIG. 21 show several examples of RS multiplexing for different UEs 102 with pattern 1 where two RS symbols are used in every 7 symbols for NCP and every 6 symbols for ECP. Different UEs 102 are assigned with different subcarriers for RS transmission in the two DMRS symbols. In the Figures, each crosshatch represents the DMRS of a different UE 102.

There is a tradeoff between the UE multiplexing capability and the number of RS symbols in each RB. In one implementation, a UE 102 may be configured with 2 subcarriers for RS transmission within each DMRS symbol. Thus, an RB can be multiplexed with 6 UEs 102.

In another implementation, a UE 102 may be configured with 3 subcarriers for RS transmission within each DMRS symbol. Thus, an RB can be multiplexed with 4 UEs 102.

In another implementation, a UE 102 may be configured with 4 subcarriers for RS transmission within each DMRS symbol. Thus, an RB can be multiplexed with 3 UEs 102.

In yet another implementation, a UE may be configured with 6 subcarriers for RS transmission within each DMRS symbol. Thus, an RB can be multiplexed with 2 UEs 102.

For CP-OFDM based transmission with 2 RS symbols in each 7 symbols for NCP and every 6 symbols for ECP, the RS can also be located at the beginning. Thus, a shifted RS pattern can be applied. FIG. 22 shows an example with NCP.

The pattern above assumes all symbols in a UL only slot is used. In case of some or all symbols of a UL centric slot, or a part of UL symbols in a UL only slot can be used for a long PUCCH, a long PUCCH design may reuse the DMRS pattern for UL only slot. That is, the DMRS location in a slot may be fixed regardless of the duration of a long PUCCH. This provides better RS multiplexing capabilities and avoids interference from UCI from other PUCCH transmissions.

Therefore, if a long PUCCH always occupies the UL symbols to the end of a UL centric or a UL only slot, the minimum number of symbols X should be 3 for a long PUCCH in a UL centric slot or UL only slot to ensure a DMRS symbol included in a long PUCCH. If a long PUCCH can be allocated with any set of symbols in a slot, the minimum number of symbols X should be 4 for normal CP to ensure a DMRS symbol included in a long PUCCH.

The same UE multiplexing orthogonal sequences can be applied for long PUCCH formats with different number of symbols as described above for DFT-S-OFDM based long PUCCH formats. Furthermore, in a long PUCCH, the RS multiplexing capability should be jointly designed with the UCI multiplexing capability. The actual UE multiplexing capability is determined by the minimum of multiplexing capabilities between the RS multiplexing capability and UCI multiplexing capability.

Similarly, the same frequency division multiplexing (FDM) combinations can be used on the pattern with a single RS symbol in every 7 symbols for NCP and every 6 symbols for ECP. In this case, the RS position should be the same as in DFT-S-OFDM based transmission, and no shift of RS position is needed. FIG. 23 shows several examples for a long PUCCH with a single DMRS in every 7 symbols for NCP with different UE multiplexing capabilities.

In one implementation, a UE 102 may be configured with 2 subcarriers for RS transmission. Thus, an RB can be multiplexed with 6 UEs 102.

In another implementation, a UE 102 may be configured with 3 subcarriers for RS transmission. Thus, an RB can be multiplexed with 4 UEs 102.

In another implementation, a UE 102 may be configured with 4 subcarriers for RS transmission. Thus, an RB can be multiplexed with 3 UEs 102.

In yet another implementation, a UE 102 may be configured with 6 subcarriers for RS transmission. Thus, an RB can be multiplexed with 2 UEs 102.

To achieve UE multiplexing, the same or similar orthogonal sequence can be applied on the time domain or frequency domain as in the case with 2 DMRS every 7 symbols for NCP and every 6 symbols for ECP.

The pattern above assumes all symbols in a UL only slot is used. In a case where some or all symbols of a UL centric slot, or a part of UL symbols in a UL only slot can be used for a long PUCCH, the long PUCCH should reuse the DMRS pattern of a UL only slot. Therefore, the minimum number of symbols X should be 4 for a long PUCCH in a UL centric slot or a UL only slot to ensure a DMRS symbol included in a long PUCCH. If two UEs 102 are multiplexed in the same RB resource, the same orthogonal sequences can be applied on each UCI carrying symbol.

Furthermore, in a long PUCCH, the RS multiplexing capability should be jointly designed with the UCI multiplexing capability. The actual UE multiplexing capability is determined by the minimum of multiplexing capabilities between the RS multiplexing capability and UCI multiplexing capability. Therefore, in case of more than two UEs 102 are multiplexed on a RB using a RS pattern, the UCI multiplexing capability may be redesigned similar to the two DMRS symbol case.

In one format, within each RB, different UCI symbols are transmitted on different OFDM symbols, and spreading factor is applied at frequency domain with the Z-C sequence. This is similar to LTE PUCCH Format 2. The same structure can be used in a long PUCCH occupying all symbols or some symbols of a UL centric slot or some symbols of a UL only slot. This results in a reduced number of UCI carrying symbols compared with a long PUCCH occupying all symbols of a UL only slot.

Also in this format, the frequency domain multiplexing may apply a length 12 orthogonal covering code in each RB instead of Z-C sequence. This allows multiple UCI symbols to be carried on different subcarriers. The same length 12 OCC codes in frequency domain defined above for DFT-S-OFDM based PUCCH can be used for CP-OFDM based PUCCH as well.

In another format, within each RB, different UCI symbols are transmitted on different subcarriers, and spreading factor is applied at time domain with the orthogonal sequences since a long PUCCH occupying part of a slot in a UL centric slot or UL only slot may have different number of UL symbols.

If all symbols are used, up to 6 orthogonal sequences of length 6 can be generated (e.g., with the following sequences in Table 14). If only some symbols are used, the number of orthogonal sequences may be reduced with a reduced length, and the corresponding orthogonal sequences with length of 2, 3, 4, and 5 above can be used. Table 16 provides an orthogonal sequence w_(n) _(oc) (i) for a 6 symbol spreading.

TABLE 16 Sequence Orthogonal sequence [w_(n) _(oc) (0) Λ w_(n) _(oc) (N_(SF) ^(PUCCH) − 1)] index n_(oc) N_(SF) ^(PUCCH) = 6 0 [1 1 1 1 1 1] 1 [1 e^(j2π/3) e^(j4π/3) 1 e^(j2π/3) e^(j4π/3)] 2 [1 e^(j4π/3) e^(j2π/3) 1 e^(j4π/3) e^(j2π/3)] 3 [1 1 1 −1 −1 −1] 4 [1 e^(j2π/3) e^(j4π/3) −1 e^(j5π/3) e^(jπ/3)] 5 [1 e^(j4π/3) e^(j2π/3) −1 e^(jπ/3) e^(j5π/3)]

For frequency hopping of a long PUCCH with CP-OFDM, the same methods as in DFT-S-OFDM based long PUCCH can be used. In one method, a fixed DMRS pattern in a slot as discussed above can be applied to any long PUCCH duration in a slot, regardless of the starting and ending symbol within the slot. This may provide better DMRS alignment among long PUCCHs with different durations.

In another method, a fixed DMRS pattern as discussed above can be applied from the starting symbol on any long PUCCH durations. Thus, the fixed pattern is corresponding to the starting symbol of a long PUCCH instead of the beginning of a slot.

Therefore, with fixed DMRS patterns relative to a slot boundary or the starting symbol of a long PUCCH, frequency hopping may be disabled if there is only 1 DMRS in the long PUCCH duration. If there are 2 or more DMRSs in the long PUCCH duration within a slot, in one approach, frequency hopping may be mandatory. In another approach, whether frequency hopping is applied may be configured by higher layer signaling.

Compared with the fixed DMRS patterns for DFT-S-OFDM based long PUCCH, the DMRS pattern for CP-OFDM based long PUCCH may be shifted (e.g., front loaded DMRS in each hop).

With fixed DMRS patterns relative to a slot boundary or the starting symbol of a long PUCCH, the frequency hopping location may also be fixed based on the DMRS patterns. Depending on the starting and ending symbols of a long PUCCH in a slot, only 1 hop should be supported. The hopping location is determined based on the closest location to the middle of the long PUCCH duration of N symbols (i.e., the closest fixed hopping location relative to the end of the Xth symbol where X=floor(N/2) [or ceil(N/2)]).

In yet another method, the DMRS location is determined in each hop based on basic structures of building blocks of different length, same as DFT-S-OFDM based long PUCCH. The DMRS for CP-OFDM based PUCCH in each hop may be shifted compared with DFT-S-OFDM based PUCCH.

This method provides optimal DMRS locations for all long PUCCH durations between 4-14 symbols. With this method, the long PUCCH may be included in a single slot, or in continuous symbols cross over in multiple slots. It should be noted that the frequency hopping may be mandatory for all long PUCCH lengths in a slot.

It should also be noted that the method can be used to determine the DMRS location/pattern regardless whether frequency hopping is configured or not on a long PUCCH. Two approaches can be considered if frequency hopping is not configured. In one approach, for any long PUCCH lengths between 4-14 symbols, the same DMRS position is determined as if frequency hopping is configured. In another approach, if the long PUCCH duration is between 4-7 symbols inclusively, the DMRS position may be determined with the pattern of one hop as described in connection with in FIG. 18.

As described above, for CP-OFDM-based long PUCCH, the DMRS symbol locations can be used as in DFT-S-OFDM-based long PUCCH. On the other hand, CP-OFDM-based long PUCCH can be more flexible on DMRS pattern. For example, the DMRS locations can be spread in the frequency domain other than time domain. FIG. 24 shows several examples of DMRS spreads in the frequency domain on 2 subcarriers, 3 subcarriers and 4 subcarriers within each RB for NCP. For each number of RS in a RB, two potential DMRS locations are provided.

For DMRS multiplexing, different orthogonal sequences may be applied for different UEs 102. The number of available orthogonal sequence depends on the number of symbols in a slot used for the long PUCCH format. For example, in a UL only slot with length of 7 or 14 for normal CP or 6 or 12 for extended CP, the number of orthogonal sequence can be the same as the number of symbols in a slot.

On the other hand, if a long PUCCH is configured in a UL centric slot, the minimum number of symbols of a long PUCCH can be X=3. The number of orthogonal sequences for a long PUCCH in a UL centric slot is the same as the number of symbols of the long PUCCH in the UL centric slot.

Alternatively, for DMRS UE multiplexing, different UEs 102 can be allocated with different symbols in the time domain with a DMRS pattern. FIG. 25 shows several examples where four UEs 102 are multiplexed with different DMRS patterns. In FIG. 25, each crosshatch represents the DMRS pattern of a given UE 102.

For UCI data, orthogonal sequences can be applied on either a time domain or a frequency domain for UE multiplexing. If an orthogonal sequence is spread in the time domain, the sequence length can be 7 for NCP, and 6 for ECP. If an orthogonal sequence is spread in the frequency domain, the sequence length can be the number of subcarriers per RB minus the number of subcarriers for DMRS.

In a case where some or all symbols of a UL centric slot, or a part of UL symbols in a UL only slot can be used for a long PUCCH, the minimum number of symbols of a long PUCCH can be X=3 or X=4 to ensure at least two DMRS symbols present for each UE 102.

In a long PUCCH in a UL centric slot, for UCI data, orthogonal sequences can be applied on either time domain or frequency domain for UE multiplexing. If an orthogonal sequence is spread at time domain, the number of orthogonal sequences, thus the sequence length can be the same as the number of symbols for the long PUCCH in the UL centric slot. If an orthogonal sequence is spread at frequency domain, the sequence length can be the number of subcarriers per RB minus the number of subcarriers for DMRS.

Configuration of a long PUCCH is also described herein. For a long PUCCH, both continuous and distributed resource allocation should be supported. The PUCCH resource allocation may be performed in RB level. In one method, a long PUCCH resource can be configured localized in contiguous RBs in a PUCCH region/subband. In another method, a long PUCCH resource can be configured in a distributed manner with non-contiguous RBs in a PUCCH region/subband. In this case, a PUCCH resource pattern should be configured with a PUCCH region/subband for a given UE 102. If a single PUCCH region/subband is configured, the size and the position of the PUCCH region/subband can be configured.

To provide frequency diversity, frequency hopping of a long PUCCH can be configured. In this case, separate PUCCH regions or subbands should be configured for a UE 102, and the PUCCH can be transmitted with frequency hopping in different regions/subbands, as shown in FIG. 26.

In one method, if a long PUCCH spans over multiple slots, frequency hopping can be applied at the slot level. Thus, adjacent slots are transmitted at different control regions/subbands.

In another method, if a long PUCCH spans over multiples of 7 symbols for NCP or multiples of 6 symbols for ECP, frequency hopping can be applied on every 7 symbols for NCP and every 6 symbols for ECP. Thus, different control regions/subbands are switched every 7 symbols for NCP and every 6 symbols for ECP. This method is slightly different from the above method. For example, a slot may have 7 or 14 symbols depending on the frequency band. Thus, this method has sub-slot frequency hopping if a slot has 14 symbols. This can be an inter-slot hopping if a slot is 7 symbols for NCP and every 6 symbols for ECP. This can be an intra-slot hopping if a slot is 14 symbols for NCP and 12 symbols for ECP.

In yet another method, if a long PUCCH occupies a single slot of 7 symbols for NCP or 6 symbols for ECP, frequency hopping can be applied at sub-slot symbol level, i.e. the first 4 symbols for NCP and first 3 symbols for ECP are transmitted in one control subband, and the remaining 3 symbols are transmitted in another control subband. In one approach, this sub-slot frequency hopping method can be used for all lengths of a long PUCCH. This can be viewed as an intra-slot hopping. The intra-slot frequency hopping can be applied even if a long PUCCH spans over multiple slots.

The frequency hopping may not be applied in a UL centric slot if there are only 1 DMRS in the long PUCCH, or if the number of symbols is only 3 or 4 symbols.

The multiple PUCCH regions or subbands can also be viewed as a distributed resource allocation for a long PUCCH. Especially, in a transmission in unlicensed spectrum, a distributed resource mapping is important to satisfy the regulatory requirements. In a case where multiple PUCCH regions/subbands are configured, the size of each PUCCH region/subband can be configured, and the positions of PUCCH regions/subbands can be configured with a pattern within the carrier.

Similarly, a UE 102 can be configured with two PUCCH resources to provide transmit diversity. The two PUCCH resources can be configured in a single PUCCH region/subband, or different PUCCH regions/subbands. The PUCCH resources can be localized with contiguous RB allocations or distributed manner with non-contiguous RB allocations.

In LTE, multiple PUCCH formats are defined for different maximum payload sizes. Similarly in NR, multiple long PUCCH formats should be configured for different maximum payload sizes and multiplexing capabilities. Thus, the tradeoff between RS, information bits and multiplexing capabilities should be considered.

Furthermore, for a given PUCCH format, the resource allocation can be more flexible than LTE depending on the channel conditions. For UEs 102 with very good signal conditions, fewer RB resources may be allocated for a PUCCH. For UEs 102 with bad signal conditions (e.g., cell edge UEs 102), more RB resources may be allocated for a PUCCH.

Therefore, for a long PUCCH, at least the following parameters may be configured for a given UE 102: the waveform (e.g., DFT-S-OFDM or CP-OFDM); a long PUCCH may occupy multiple RBs and the number of RBs of a long PUCCH may be configured (e.g., based on the payload size); a long PUCCH may occupy one or more slots and the length of a long PUCCH can be configurable based on the payload size and delay tolerance, etc.; a tradeoff can be considered between the number of RBs and the number of slot; the RS pattern and RS position; the spreading sequence for UCI multiplexing; frequency diversity with multiple PUCCH regions/subbands; transmit diversity with two configured PUCCH resources; the location of one or more configured PUCCH regions/subbands including size and position of each PUCCH subband/region in the carrier; and localized or distributed resource allocation for a PUCCH resource in a PUCCH region/subband.

In order to reduce the signaling overhead, a list of supported long uplink control channel formats can be specified, each with a given set of parameters, and the name or index of a supported long PUCCH format may be indicated or configured to a UE 102.

Band specific considerations of a long PUCCH are also described herein. The 5G NR supports different frequency bands with different channel characteristics. Thus, the PUCCH behavior may be different for different frequency bands. For below 6 GHz frequency bands, the channel condition is more stable. Thus, it is better to use a semi-static configured PUCCH resource, or a dynamic indicated PUCCH resource.

Besides reusing the same DMRS positions as in a long PUCCH spans over all symbols in a slot, for a long PUCCH in a partial slot (e.g., in a UL centric or UL only slot), the DMRS positions can also configured by RRC signaling or indicated by physical layer signaling. In this case, the DMRS locations may be different from a long PUCCH spans over all symbols in a slot. However, the same orthogonal sequences and/or RS patterns described before can be applied on the RS REs, and the same orthogonal sequences described before for UCI carrying REs can also reused.

For frequency band above 6 GHz, beamforming technology is critical for operation. Considering beam sweeping, a UE 102 may use different beams in different symbols, the DMRS from different symbols may not be appropriate for decoding of a different symbol. Thus, several methods can be considered for long PUCCH format at higher frequency bands above 6 GHz.

In a first method (Method 1), a long PUCCH can be configured with less number of symbols with the same beam in time domain and more RBs in frequency domain. For example, the long PUCCH can be limited to 7 symbols for NCP and 6 symbols for ECP, or limited to a single slot length.

In a second method (Method 2), a long PUCCH can be configured with a beam pattern (i.e., a pattern for the symbols with the same beam). The symbols of a long PUCCH may be spread over the beam pattern.

In a third method (Method 3), a long PUCCH can use self-contained DMRS in each symbol. The UE multiplexing within a RB can be reduced or eliminated. Furthermore, DMRS of 1 symbol short PUCCH can be used in each symbol. FIG. 27 shows the reference signal pattern designs. For each RS setting, at least two patterns can be defined, denoted as pattern 1 and pattern 2 without loss of generality. Staggered DMRS pattern or different DMRS patterns can be applied on different symbols. The UE 102 may use contiguous symbols or non-contiguous symbols defined by a symbol pattern. The symbol pattern may be configured by the gNB 160. The same beam can be applied on the symbols in the symbol pattern. Or different beams can be applied on the symbols in the symbol pattern if self-contained DMRS is used in each symbol.

For a long PUCCH above 6 GHz frequency band, in one method, the gNB 160 may indicate which symbols and/or beams should be used for long PUCCH transmission by semi-static higher layer singling or dynamic signaling via DCI. To determine the long PUCCH resource, 5G NR requires more configurations. At least one of the following aspects may be supported in NR. A long PUCCH format and/or resource for a UE 102 can be semi-statically configured by higher layer signaling. A long PUCCH format and/or resource for a UE 102 can be dynamically indicated by physical layer signaling (e.g., a DCI). Different long PUCCH formats may be configured or utilized for different types of UCI feedback and payload sizes.

The PUCCH resource configuration has a tradeoff between semi-static RRC signaling and dynamic DCI indication. In general, the PUCCH format/structure should be configured by RRC signaling, and the actual PUCCH resource to be used for UCI reporting should be determined by explicit DCI indication.

Therefore, a UE 102 can be configured with a set of long PUCCH resources with detailed parameters. The parameters include the PUCCH formats, the resource allocation, etc. And the DCI indicates the long PUCCH index within the RRC configured set of resources. In another method, the PUCCH resources may be indexed based on a RRC configured long PUCCH structure. A UE 102 may be configured with a set of PUCCH resources based on the PUCCH indexes. The DCI indicates the index of a PUCCH resource in a set of PUCCH resources configured for a UE 102.

PUCCH considerations for URLLC are also described herein. For ultra-reliable low latency communications (URLLC) traffic, several aspects need to be considered for PUCCH transmissions. URLLC traffic requires ultra-reliability and low latency, and may collide with a PUCCH or PUSCH transmission of the same UE 102. As a general rule, the URLLC traffic should have higher priority than any other UL transmissions.

In the case where a PUCCH transmission collides with a URLLC traffic in the same symbol, the URLLC should have higher priority. Several methods can be considered.

In a first method (Method 1), URLLC traffic is transmitted and the PUCCH in the overlapping symbol is dropped. This is a simple solution and can be applicable in all cases regardless of PUCCH waveforms and/or numerologies. The whole short PUCCH should be dropped for a 1-symbol PUCCH. For a 2-symbol PUCCH, if the URLLC collides with the first symbol of a short PUCCH, all short PUCCH symbols should be dropped. If a 2-symbol short PUCCH transmission already starts, and the URLLC collides with the 2nd symbol in a 2-symbol short PUCCH, the second symbol of the short PUCCH is dropped.

For a long PUCCH transmission, the over lapping symbols should be dropped to give higher priority to a URLLC transmission. A long PUCCH transmission may resume after the URLLC transmission. The UE 102 may drop the remaining long PUCCH transmission if the number of PUCCH symbols punctured by the URLLC is above a threshold because the PUCCH is not likely to be decoded correctly. The threshold value may be semi-statically configured for a given long PUCCH format.

In a second method (Method 2), simultaneous transmission of URLLC and PUCCH may be performed, with power scaling on PUCCH if necessary. If simultaneous transmission of URLLC and PUCCH is supported on the same symbol, UL transmit power should be allocated to the URLLC traffic first. The remaining power can be power scaled on the PUCCH REs in the same UL symbol. This can be applied if the PUCCH REs does not overlap with URLLC transmission REs.

In case of overlapping REs between URLLC and PUCCH, the URLLC signals are transmitted and PUCCH symbols on corresponding REs may be dropped. In another alternative, in case of overlapping REs between URLLC and PUCCH, the URLLC signals are transmitted and entire PUCCH symbol should be dropped as in method 1.

It should be noted that if URLLC traffic and PUCCH uses different waveforms, simultaneous transmission of URLLC and PUCCH may not be possible. Also, if URLLC traffic and PUCCH uses different numerologies, some guard interval may be required between different numerologies, and simultaneous transmission of URLLC and PUCCH may not be supported in some cases.

The UE operations module 124 may provide information 148 to the one or more receivers 120. For example, the UE operations module 124 may inform the receiver(s) 120 when to receive retransmissions.

The UE operations module 124 may provide information 138 to the demodulator 114. For example, the UE operations module 124 may inform the demodulator 114 of a modulation pattern anticipated for transmissions from the gNB 160.

The UE operations module 124 may provide information 136 to the decoder 108. For example, the UE operations module 124 may inform the decoder 108 of an anticipated encoding for transmissions from the gNB 160.

The UE operations module 124 may provide information 142 to the encoder 150. The information 142 may include data to be encoded and/or instructions for encoding. For example, the UE operations module 124 may instruct the encoder 150 to encode transmission data 146 and/or other information 142. The other information 142 may include PDSCH HARQ-ACK information.

The encoder 150 may encode transmission data 146 and/or other information 142 provided by the UE operations module 124. For example, encoding the data 146 and/or other information 142 may involve error detection and/or correction coding, mapping data to space, time and/or frequency resources for transmission, multiplexing, etc. The encoder 150 may provide encoded data 152 to the modulator 154.

The UE operations module 124 may provide information 144 to the modulator 154. For example, the UE operations module 124 may inform the modulator 154 of a modulation type (e.g., constellation mapping) to be used for transmissions to the gNB 160. The modulator 154 may modulate the encoded data 152 to provide one or more modulated signals 156 to the one or more transmitters 158.

The UE operations module 124 may provide information 140 to the one or more transmitters 158. This information 140 may include instructions for the one or more transmitters 158. For example, the UE operations module 124 may instruct the one or more transmitters 158 when to transmit a signal to the gNB 160. For instance, the one or more transmitters 158 may transmit during a UL subframe. The one or more transmitters 158 may upconvert and transmit the modulated signal(s) 156 to one or more gNBs 160.

Each of the one or more gNBs 160 may include one or more transceivers 176, one or more demodulators 172, one or more decoders 166, one or more encoders 109, one or more modulators 113, a data buffer 162 and a gNB operations module 182. For example, one or more reception and/or transmission paths may be implemented in a gNB 160. For convenience, only a single transceiver 176, decoder 166, demodulator 172, encoder 109 and modulator 113 are illustrated in the gNB 160, though multiple parallel elements (e.g., transceivers 176, decoders 166, demodulators 172, encoders 109 and modulators 113) may be implemented.

The transceiver 176 may include one or more receivers 178 and one or more transmitters 117. The one or more receivers 178 may receive signals from the UE 102 using one or more antennas 180 a-n. For example, the receiver 178 may receive and downconvert signals to produce one or more received signals 174. The one or more received signals 174 may be provided to a demodulator 172. The one or more transmitters 117 may transmit signals to the UE 102 using one or more antennas 180 a-n. For example, the one or more transmitters 117 may upconvert and transmit one or more modulated signals 115.

The demodulator 172 may demodulate the one or more received signals 174 to produce one or more demodulated signals 170. The one or more demodulated signals 170 may be provided to the decoder 166. The gNB 160 may use the decoder 166 to decode signals. The decoder 166 may produce one or more decoded signals 164, 168. For example, a first eNB-decoded signal 164 may comprise received payload data, which may be stored in a data buffer 162. A second eNB-decoded signal 168 may comprise overhead data and/or control data. For example, the second eNB-decoded signal 168 may provide data (e.g., PDSCH HARQ-ACK information) that may be used by the gNB operations module 182 to perform one or more operations.

In general, the gNB operations module 182 may enable the gNB 160 to communicate with the one or more UEs 102. The gNB operations module 182 may include one or more of a gNB long PUCCH module 194. The gNB long PUCCH module 194 may implement a long PUCCH design for 5G NR as described herein.

The gNB operations module 182 may provide information 188 to the demodulator 172. For example, the gNB operations module 182 may inform the demodulator 172 of a modulation pattern anticipated for transmissions from the UE(s) 102.

The gNB operations module 182 may provide information 186 to the decoder 166. For example, the gNB operations module 182 may inform the decoder 166 of an anticipated encoding for transmissions from the UE(s) 102.

The gNB operations module 182 may provide information 101 to the encoder 109. The information 101 may include data to be encoded and/or instructions for encoding. For example, the gNB operations module 182 may instruct the encoder 109 to encode information 101, including transmission data 105.

The encoder 109 may encode transmission data 105 and/or other information included in the information 101 provided by the gNB operations module 182. For example, encoding the data 105 and/or other information included in the information 101 may involve error detection and/or correction coding, mapping data to space, time and/or frequency resources for transmission, multiplexing, etc. The encoder 109 may provide encoded data 111 to the modulator 113. The transmission data 105 may include network data to be relayed to the UE 102.

The gNB operations module 182 may provide information 103 to the modulator 113. This information 103 may include instructions for the modulator 113. For example, the gNB operations module 182 may inform the modulator 113 of a modulation type (e.g., constellation mapping) to be used for transmissions to the UE(s) 102. The modulator 113 may modulate the encoded data 111 to provide one or more modulated signals 115 to the one or more transmitters 117.

The gNB operations module 182 may provide information 192 to the one or more transmitters 117. This information 192 may include instructions for the one or more transmitters 117. For example, the gNB operations module 182 may instruct the one or more transmitters 117 when to (or when not to) transmit a signal to the UE(s) 102. The one or more transmitters 117 may upconvert and transmit the modulated signal(s) 115 to one or more UEs 102.

It should be noted that a DL subframe may be transmitted from the gNB 160 to one or more UEs 102 and that a UL subframe may be transmitted from one or more UEs 102 to the gNB 160. Furthermore, both the gNB 160 and the one or more UEs 102 may transmit data in a standard special subframe.

It should also be noted that one or more of the elements or parts thereof included in the eNB(s) 160 and UE(s) 102 may be implemented in hardware. For example, one or more of these elements or parts thereof may be implemented as a chip, circuitry or hardware components, etc. It should also be noted that one or more of the functions or methods described herein may be implemented in and/or performed using hardware. For example, one or more of the methods described herein may be implemented in and/or realized using a chipset, an application-specific integrated circuit (ASIC), a large-scale integrated circuit (LSI) or integrated circuit, etc.

FIG. 2 is a diagram illustrating one example of a resource grid for the downlink. The resource grid illustrated in FIG. 2 may be utilized in some implementations of the systems and methods disclosed herein. More detail regarding the resource grid is given in connection with FIG. 1.

In FIG. 2, one downlink subframe 269 may include two downlink slots 283. N^(DL) _(RB) downlink bandwidth configuration of the serving cell, expressed in multiples of N^(RB) _(sc), where N^(RB) _(sc) is a resource block 289 size in the frequency domain expressed as a number of subcarriers, and N^(DL) _(symb) is the number of OFDM symbols 287 in a downlink slot 283. A resource block 289 may include a number of resource elements (RE) 291.

For a PCell, N^(DL) _(RB) is broadcast as a part of system information. For an SCell (including a licensed assisted access (LAA) SCell), N^(DL) _(RB) is configured by a RRC message dedicated to a UE 102. For PDSCH mapping, the available RE 291 may be the RE 291 whose index 1 fulfils 1≥1_(data,start) and/or 1_(data,end)≥1 in a subframe.

In the downlink, the OFDM access scheme with cyclic prefix (CP) may be employed, which may be also referred to as CP-OFDM. In the downlink, PDCCH, enhanced PDCCH (EPDCCH), PDSCH and the like may be transmitted. A downlink radio frame may consist of multiple pairs of downlink resource blocks (RBs) which is also referred to as physical resource blocks (PRBs). The downlink RB pair is a unit for assigning downlink radio resources, defined by a predetermined bandwidth (RB bandwidth) and a time slot. The downlink RB pair consists of two downlink RBs that are continuous in the time domain.

The downlink RB consists of twelve sub-carriers in frequency domain and seven (for normal CP) or six (for extended CP) OFDM symbols in time domain. A region defined by one sub-carrier in frequency domain and one OFDM symbol in time domain is referred to as a resource element (RE) and is uniquely identified by the index pair (k,l) in a slot, where k and l are indices in the frequency and time domains, respectively. While downlink subframes in one component carrier (CC) are discussed herein, downlink subframes are defined for each CC and downlink subframes are substantially in synchronization with each other among CCs.

FIG. 3 is a diagram illustrating one example of a resource grid for the uplink. The resource grid illustrated in FIG. 3 may be utilized in some implementations of the systems and methods disclosed herein. More detail regarding the resource grid is given in connection with FIG. 1.

In FIG. 3, one uplink subframe 369 may include two uplink slots 383. N^(UL) _(RB) is uplink bandwidth configuration of the serving cell, expressed in multiples of N^(RB) _(sc), where N^(RB) _(sc) is a resource block 389 size in the frequency domain expressed as a number of subcarriers, and N^(UL) _(symb) is the number of SC-FDMA symbols 393 in an uplink slot 383. A resource block 389 may include a number of resource elements (RE) 391.

For a PCell, N^(UL) _(RB) is broadcast as a part of system information. For an SCell (including an LAA SCell), N^(UL) _(RB) is configured by a RRC message dedicated to a UE 102.

In the uplink, in addition to CP-OFDM, a Single-Carrier Frequency Division Multiple Access (SC-FDMA) access scheme may be employed, which is also referred to as Discrete Fourier Transform-Spreading OFDM (DFT-S-OFDM). In the uplink, PUCCH, PDSCH, PRACH and the like may be transmitted. An uplink radio frame may consist of multiple pairs of uplink resource blocks. The uplink RB pair is a unit for assigning uplink radio resources, defined by a predetermined bandwidth (RB bandwidth) and a time slot. The uplink RB pair consists of two uplink RBs that are continuous in the time domain.

The uplink RB may consist of twelve sub-carriers in frequency domain and seven (for normal CP) or six (for extended CP) OFDM/DFT-S-OFDM symbols in time domain. A region defined by one sub-carrier in the frequency domain and one OFDM/DFT-S-OFDM symbol in the time domain is referred to as a RE and is uniquely identified by the index pair (k,l) in a slot, where k and l are indices in the frequency and time domains respectively. While uplink subframes in one component carrier (CC) are discussed herein, uplink subframes are defined for each CC.

FIG. 4 shows examples of several numerologies 401. The numerology #1 401 a may be a basic numerology (e.g., a reference numerology). For example, a RE 495 a of the basic numerology 401 a may be defined with subcarrier spacing 405 a of 15 kHz in frequency domain and 2048Ts+CP length (e.g., 160Ts or 144Ts) in time domain (i.e., symbol length #1 403 a), where Ts denotes a baseband sampling time unit defined as 1/(15000*2048) seconds. For the i-th numerology, the subcarrier spacing 405 may be equal to 15*2^(i) and the effective OFDM symbol length 2048*2^(−i)*Ts. It may cause the symbol length is 2048*2^(−i)*Ts+CP length (e.g., 160*2^(−i)*Ts or 144*2^(−i)*Ts). In other words, the subcarrier spacing of the i+1-th numerology is a double of the one for the i-th numerology, and the symbol length of the i+1-th numerology is a half of the one for the i-th numerology. FIG. 4 shows four numerologies, but the system may support another number of numerologies. Furthermore, the system does not have to support all of the 0-th to the I-th numerologies, i=0, 1, . . . , I.

FIG. 5 shows examples of subframe structures for the numerologies 501 that are shown in FIG. 4. Given that a slot 283 includes N^(DL) _(symb (or N) ^(UL) _(symb))=7 symbols, the slot length of the i+1-th numerology 501 is a half of the one for the i-th numerology 501, and eventually the number of slots 283 in a subframe (i.e., 1 ms) becomes double. It may be noted that a radio frame may include 10 subframes, and the radio frame length may be equal to 10 ms.

FIG. 6 shows examples of slots 683 and sub-slots 607. If a sub-slot 607 is not configured by higher layer, the UE 102 and the eNB/gNB 160 may only use a slot 683 as a scheduling unit. More specifically, a given transport block may be allocated to a slot 683. If the sub-slot 607 is configured by higher layer, the UE 102 and the eNB/gNB 160 may use the sub-slot 607 as well as the slot 683. The sub-slot 607 may include one or more OFDM symbols. The maximum number of OFDM symbols that constitute the sub-slot 607 may be N^(DL) _(symb)−1 (or N^(UL) _(symb)−1).

The sub-slot length may be configured by higher layer signaling. Alternatively, the sub-slot length may be indicated by a physical layer control channel (e.g., by DCI format).

The sub-slot 607 may start at any symbol within a slot 683 unless it collides with a control channel. There could be restrictions of mini-slot length based on restrictions on starting position. For example, the sub-slot 607 with the length of N^(DL) _(symb)−1 (or N^(UL) _(symb)−1) may start at the second symbol in a slot 683. The starting position of a sub-slot 607 may be indicated by a physical layer control channel (e.g., by DCI format). Alternatively, the starting position of a sub-slot 607 may be derived from information (e.g., search space index, blind decoding candidate index, frequency and/or time resource indices, PRB index, a control channel element index, control channel element aggregation level, an antenna port index, etc.) of the physical layer control channel which schedules the data in the concerned sub-slot 607.

In cases when the sub-slot 607 is configured, a given transport block may be allocated to either a slot 683, a sub-slot 607, aggregated sub-slots 607 or aggregated sub-slot(s) 607 and slot 683. This unit may also be a unit for HARQ-ACK bit generation.

FIG. 7 shows examples of scheduling timelines 709. For a normal DL scheduling timeline 709 a, DL control channels are mapped the initial part of a slot 783 a. The DL control channels 711 schedule DL shared channels 713 a in the same slot 783 a. HARQ-ACKs for the DL shared channels 713 a (i.e., HARQ-ACKs each of which indicates whether or not transport block in each DL shared channel 713 a is detected successfully) are reported via UL control channels 715 a in a later slot 783 b. In this instance, a given slot 783 may contain either one of DL transmission and UL transmission.

For a normal UL scheduling timeline 709 b, DL control channels 711 b are mapped the initial part of a slot 783 c. The DL control channels 711 b schedule UL shared channels 717 a in a later slot 783 d. For these cases, the association timing (time shift) between the DL slot 783 c and the UL slot 783 d may be fixed or configured by higher layer signaling. Alternatively, it may be indicated by a physical layer control channel (e.g., the DL assignment DCI format, the UL grant DCI format, or another DCI format such as UE-common signaling DCI format which may be monitored in common search space).

For a self-contained base DL scheduling timeline 709 c, DL control channels 711 c are mapped to the initial part of a slot 783 e. The DL control channels 711 c schedule DL shared channels 713 b in the same slot 783 e. HARQ-ACKs for the DL shared channels 713 b are reported in UL control channels 715 b, which are mapped at the ending part of the slot 783 e.

For a self-contained base UL scheduling timeline 709 d, DL control channels 711 d are mapped to the initial part of a slot 783 f. The DL control channels 711 d schedule UL shared channels 717 b in the same slot 783 f. For these cases, the slot 783 f may contain DL and UL portions, and there may be a guard period between the DL and UL transmissions.

The use of a self-contained slot may be upon a configuration of self-contained slot. Alternatively, the use of a self-contained slot may be upon a configuration of the sub-slot. Yet alternatively, the use of a self-contained slot may be upon a configuration of shortened physical channel (e.g., PDSCH, PUSCH, PUCCH, etc.).

FIG. 8 shows examples of DL control channel monitoring regions. One or more sets of PRB(s) may be configured for DL control channel monitoring. In other words, a control resource set is, in the frequency domain, a set of PRBs within which the UE 102 attempts to blindly decode downlink control information, where the PRBs may or may not be frequency contiguous, a UE 102 may have one or more control resource sets, and one DCI message may be located within one control resource set. In the frequency-domain, a PRB is the resource unit size (which may or may not include DM-RS) for a control channel. A DL shared channel may start at a later OFDM symbol than the one(s) which carries the detected DL control channel. Alternatively, the DL shared channel may start at (or earlier than) an OFDM symbol than the last OFDM symbol which carries the detected DL control channel. In other words, dynamic reuse of at least part of resources in the control resource sets for data for the same or a different UE 102, at least in the frequency domain may be supported.

FIG. 9 shows examples of DL control channel which consists of more than one control channel elements. When the control resource set spans multiple OFDM symbols, a control channel candidate may be mapped to multiple OFDM symbols or may be mapped to a single OFDM symbol. One DL control channel element may be mapped on REs defined by a single PRB and a single OFDM symbol. If more than one DL control channel elements are used for a single DL control channel transmission, DL control channel element aggregation may be performed.

The number of aggregated DL control channel elements is referred to as DL control channel element aggregation level. The DL control channel element aggregation level may be 1 or 2 to the power of an integer. The gNB 160 may inform a UE 102 of which control channel candidates are mapped to each subset of OFDM symbols in the control resource set. If one DL control channel is mapped to a single OFDM symbol and does not span multiple OFDM symbols, the DL control channel element aggregation is performed within an OFDM symbol, namely multiple DL control channel elements within an OFDM symbol are aggregated. Otherwise, DL control channel elements in different OFDM symbols can be aggregated.

FIG. 10 shows examples of UL control channel structures. UL control channel may be mapped on REs which are defined a PRB and a slot in frequency and time domains, respectively. This UL control channel may be referred to as a long format (or just the 1st format). UL control channels may be mapped on REs on a limited OFDM symbols in time domain. This may be referred to as a short format (or just the 2nd format). The UL control channels with a short format may be mapped on REs within a single PRB. Alternatively, the UL control channels with a short format may be mapped on REs within multiple PRBs. For example, interlaced mapping may be applied, namely the UL control channel may be mapped to every N PRBs (e.g. 5 or 10) within a system bandwidth.

FIG. 11 is a block diagram illustrating one implementation of an gNB 1160. The gNB 1160 may include a higher layer processor 1123, a DL transmitter 1125, a UL receiver 1133, and one or more antenna 1131. The DL transmitter 1125 may include a PDCCH transmitter 1127 and a PDSCH transmitter 1129. The UL receiver 1133 may include a PUCCH receiver 1135 and a PUSCH receiver 1137.

The higher layer processor 1123 may manage physical layer's behaviors (the DL transmitter's and the UL receiver's behaviors) and provide higher layer parameters to the physical layer. The higher layer processor 1123 may obtain transport blocks from the physical layer. The higher layer processor 1123 may send/acquire higher layer messages such as an RRC message and MAC message to/from a UE's higher layer. The higher layer processor 1123 may provide the PDSCH transmitter transport blocks and provide the PDCCH transmitter transmission parameters related to the transport blocks.

The DL transmitter 1125 may multiplex downlink physical channels and downlink physical signals (including reservation signal) and transmit them via transmission antennas 1131. The UL receiver 1133 may receive multiplexed uplink physical channels and uplink physical signals via receiving antennas 1131 and de-multiplex them. The PUCCH receiver 1135 may provide the higher layer processor 1123 UCI. The PUSCH receiver 1137 may provide the higher layer processor 1123 received transport blocks.

FIG. 12 is a block diagram illustrating one implementation of a UE 1202. The UE 1202 may include a higher layer processor 1223, a UL transmitter 1251, a DL receiver 1243, and one or more antenna 1231. The UL transmitter 1251 may include a PUCCH transmitter 1253 and a PUSCH transmitter 1255. The DL receiver 1243 may include a PDCCH receiver 1245 and a PDSCH receiver 1247.

The higher layer processor 1223 may manage physical layer's behaviors (the UL transmitter's and the DL receiver's behaviors) and provide higher layer parameters to the physical layer. The higher layer processor 1223 may obtain transport blocks from the physical layer. The higher layer processor 1223 may send/acquire higher layer messages such as an RRC message and MAC message to/from a UE's higher layer. The higher layer processor 1223 may provide the PUSCH transmitter transport blocks and provide the PUCCH transmitter 1253 UCI.

The DL receiver 1243 may receive multiplexed downlink physical channels and downlink physical signals via receiving antennas 1231 and de-multiplex them. The PDCCH receiver 1245 may provide the higher layer processor 1223 DCI. The PDSCH receiver 1247 may provide the higher layer processor 1223 received transport blocks.

It should be noted that names of physical channels described herein are examples. The other names such as “NRPDCCH, NRPDSCH, NRPUCCH and NRPUSCH”, “new Generation-(G)PDCCH, GPDSCH, GPUCCH and GPUSCH” or the like can be used.

FIG. 13 illustrates several examples of long PUCCH duration design. In the example of FIG. 13(a), a long PUCCH spans over the whole UL only slot.

In the example of FIG. 13(b), a long PUCCH spans over multiple UL only slots.

In the example of FIG. 13(c), a long PUCCH spans over the whole UL centric slot.

In the example of FIG. 13(d), a long PUCCH spans over the whole UL centric slot and one or more consecutive UL only slots.

In the example of FIG. 13(e), a long PUCCH spans over some symbols to the end of a UL centric slot or a UL only slot.

In the example of FIG. 13(f), a long PUCCH spans over some symbols to the end of a UL centric slot or a UL only slot and one or more consecutive UL only slots.

In the example of FIG. 13(g), a long PUCCH spans over some symbols of a UL centric slot or a UL only slot.

In the example of FIG. 13(h), a long PUCCH starts in the middle of a UL centric slot or a UL only slot. The long PUCCH spans over one or more consecutive UL only slots and ends in the middle of a UL only slot.

FIG. 14 illustrates examples of two demodulation reference signals (DMRS) 1401 in every 7 symbols for normal cyclic prefix (NCP) or 6 symbols for extended cyclic prefix (ECP). A first DMRS pattern (Pattern 1) 1403 includes 2 RS in every 7 or 6 symbols. With this pattern, a long PUCCH format has 2 DMRS 1401 in every 7 symbols for normal CP (NCP), and 2 DMRS 1401 in every 6 symbols for extended CP (ECP) within a slot.

A first example (a) shows a DMRS pattern 1 1403 a for Normal cyclic prefix (CP). A second example (b) shows a DMRS pattern 1 1403 b for extended CP.

FIG. 15 illustrates examples of the minimum number of symbols for a long PUCCH. In the example of FIG. 15(a), X=3 if the long PUCCH covers the end of a slot. In the example of FIG. 15(b), X=4 if the long PUCCH can start/end at any symbol of a slot.

In FIG. 15, there are symbols depicted that that are not used or allocated for a long PUCCH. The remaining symbols (including a DMRS symbol) are allocated for a long PUCCH. Thus, in FIG. 15(a), it is a long PUCCH at the last 3 symbols. In FIG. 15(b), it is a long PUCCH allocated in the middle of the slot, from the 2nd to 5th symbols.

FIG. 16 illustrates examples of one DMRS 1601 in every 7 symbols for NCP or 6 symbols for ECP. A second DMRS pattern (Pattern 2) 1603 includes one RS in every 7 or 6 symbols. With this pattern, a long PUCCH format has 1 DMRS 1601 in every 7 symbols for normal CP (NCP), and 1 DMRS 1601 in every 6 symbols for extended CP (ECP) within a slot.

A first example (a) shows a DMRS pattern 2 1603 a for Normal cyclic prefix (CP). A second example (b) shows a DMRS pattern 2 1603 b for extended CP.

FIG. 17 illustrates fixed hopping candidates for PUCCH based on fixed DMRS patterns. In a first example, 2 DMRS symbols may be in every 7 symbols for normal CP. In a second example, 2 DMRS symbols may be in every 7 symbols for extended CP. In a third example, 1 DMRS symbol may be in every 7 symbols for normal CP. In a fourth example, 1 DMRS symbol may be in every 7 symbols for extended CP.

Fixed frequency hopping location candidates are also depicted in FIG. 17. Depending on the starting and ending symbols of a long PUCCH in a slot, only 1 hop may be supported. The hopping location may be determined based on the closest location to the middle of the long PUCCH duration of N symbols. In other words, hopping location may be determined based on the closest fixed hopping location relative to the end of the Xth symbol where X=floor(N/2) [or ceil(N/2)].

FIG. 18 illustrates examples of PUCCH DMRS basic blocks in a hop. PUCCH from 2 to 7 symbols are depicted. In one configuration, the PUCCH may have 1 DMRS. In another configuration, the PUCCH may have 2 DMRSs. The DMRS location may be determined in each hop based on basic structures of building blocks of different length. Since the long PUCCH duration in a slot may vary between 4-14 symbols, if frequency hopping is applied, each hop may have 2 to 7 symbols.

Each hopping may have 1 or 2 DMRSs. For a single hop length greater than or equal to 4 symbols, whether 1 or 2 DMRSs in a hop may be configured by higher layer signaling.

For a slot with 6 symbols for extended CP or 7 symbols for normal CP, if frequency hopping is not configured or supported, a long PUCCH may be configured with 1 or 2 DMRS following the pattern in the basic blocks. For normal CP, the 4 to 7 symbols structures can be applied in a long PUCCH. For extended CP, the 4 to 6 symbols structures can be applied in a long PUCCH. The long PUCCH may be configured with either 1 DMRS or 2 DMRS symbols.

If frequency hopping is configured or supported, the hopping location may be determined at the middle of a given long PUCCH with length of N symbols, where N is greater than or equal to 4, and smaller than or equal to the number of symbols in a slot. The hop may occur at the end of the Xth symbol where X=floor(N/2) or ceil(N/2). Then, the DMRS positions are determined based on the length of each hop from the basic building blocks of each length and the number of DMRS configured for each hop if applicable. The basic blocks of 2-4 symbol structures can be applied in each hop. FIG. 18 shows the frequency hopping locations for long PUCCH duration of 4-7 symbols if configured. Two DMRS are required if frequency hopping is configured for a long PUCCH.

For a slot with 12 symbols for extended CP or 14 symbols for normal CP, if the length of a long PUCCH is smaller than or equal to 6 symbols for extended CP or smaller than or equal to 7 symbols for normal CP, the same method as described above is used. In other words, if frequency hopping is not configured or supported, a long PUCCH may be configured with 1 or 2 DMRS following the pattern in the basic blocks. For normal CP, the 4 to 7 symbols structures can be applied in a long PUCCH. For extended CP, the 4 to 6 symbols structures can be applied in a long PUCCH. The long PUCCH may be configured with either 1 DMRS or 2 DMRS symbols.

If frequency hopping is configured or supported, the hopping location is determined at the middle of a given long PUCCH with length of N symbols, where N is greater or equal to 4, and smaller or equal to the number of symbols in a slot. The hop may occur at the end of the Xth symbol where X=floor(N/2) or ceil(N/2). Then, the DMRS positions are determined based on the length of each hop from the basic building blocks of each length and the number of DMRS configured for each hop if applicable. The basic blocks of 2-4 symbol structures can be applied in each hop. FIG. 18 shows the frequency hopping locations for long PUCCH duration of 4-7 symbols if configured. Two DMRS are required if frequency hopping is configured for a long PUCCH.

If the length of a long PUCCH is greater than 6 symbols for extended CP or greater than 7 symbols for normal CP, first, the hopping location may be determined at the middle of a given long PUCCH with length of N symbols, where N is greater than or equal to 6 for extended CP and greater than 7 for normal CP, and is smaller than or equal to the number of symbols in a slot. The hop may occur at the end of the Xth symbol where X=floor(N/2) or ceil(N/2). Then, the DMRS positions are determined based on the length of each hop from the basic building blocks of each length and the number of DMRS configured for each hop if applicable. The basic blocks of 4-7 symbol structures can be applied in each hop. It should be noted that the same structure may be applied regardless whether frequency hopping is configured or not.

This method provides optimal DMRS locations for all long PUCCH durations between 4-14 symbols. With this method, the long PUCCH may be included in a single slot, or in continuous symbols cross over in multiple slots. It should be noted that the frequency hopping may be mandatory for all long PUCCH lengths in a slot.

The method can be used to determine the DMRS location/pattern regardless whether frequency hopping is configured or not on a long PUCCH. Two approaches can be considered if frequency hopping is not configured. In one approach, for any long PUCCH lengths between 4-14 symbols, the same DMRS position is determined as if frequency hopping is configured. In another approach, if the long PUCCH duration is between 4-7 symbols inclusively, the DMRS position may be determined with the pattern of one hop given in FIG. 18.

FIGS. 19A and 19B illustrate examples of DMRS patterns for different durations. In one case, long PUCCH may be configured with 1 DMRS symbol in a hop. In another case, long PUCCH may be configured with 2 DMRS symbol in a hop. The DMRS patterns and frequency hopping location for 1 or 2 DMRSs are shown for long PUCCH durations.

In FIG. 19A, for PUCCH length of 4 to 7 symbols, if there is only one DMRS, no frequency hopping is supported, as shown on the left side under 1 DMRS in a hop. For PUCCH length of 4 to 7 symbols, if there are two DMRS symbols, frequency hopping may be supported with the given location as shown on the right side under 2 DMRS in a hop. It should be noted that in this case, there may be only 1 DMRS in each hop if frequency hopping is applied.

FIG. 20 illustrates examples of RS patterns with frequency division multiplexing (FDM) among UEs for two DMRS in every 7 symbols for NCP. Different UEs 102 are assigned with different RS patterns that are not overlapping with other UEs 102. FIG. 20 shows several examples of RS multiplexing for different UEs 102 with pattern 1 where two RS symbols are used in every 7 symbols for NCP. Different UEs 102 are assigned with different subcarriers for RS transmission in the two DMRS symbols. In the Figures, each crosshatch represents the DMRS of a different UE.

In implementation (a), a UE 102 may be configured with 2 subcarriers for RS transmission within each DMRS symbol. Thus, an RB can be multiplexed with 6 UEs 102.

In implementation (b), a UE 102 may be configured with 3 subcarriers for RS transmission within each DMRS symbol. Thus, an RB can be multiplexed with 4 UEs 102.

In implementation (c), a UE 102 may be configured with 4 subcarriers for RS transmission within each DMRS symbol. Thus, an RB can be multiplexed with 3 UEs 102.

In implementation (d), a UE may be configured with 6 subcarriers for RS transmission within each DMRS symbol. Thus, an RB can be multiplexed with 2 UEs 102.

FIG. 21 illustrates examples of RS patterns with FDM among UEs for two DMRS in every 6 symbols for ECP. Different UEs 102 are assigned with different RS patterns that are not overlapping with other UEs 102. FIG. 21 shows several examples of RS multiplexing for different UEs 102 with pattern 1 where two RS symbols are used in every 6 symbols for ECP. Different UEs 102 are assigned with different subcarriers for RS transmission in the two DMRS symbols.

In implementation (a), a UE 102 may be configured with 2 subcarriers for RS transmission within each DMRS symbol. Thus, an RB can be multiplexed with 6 UEs 102.

In implementation (b), a UE 102 may be configured with 3 subcarriers for RS transmission within each DMRS symbol. Thus, an RB can be multiplexed with 4 UEs 102.

In implementation (c), a UE 102 may be configured with 4 subcarriers for RS transmission within each DMRS symbol. Thus, an RB can be multiplexed with 3 UEs 102.

In implementation (d), a UE may be configured with 6 subcarriers for RS transmission within each DMRS symbol. Thus, an RB can be multiplexed with 2 UEs 102.

FIG. 22 illustrates examples of a shifted RS pattern with FDM among UEs for two DMRS in every 7 symbols for NCP. For CP-OFDM based transmission with 2 RS symbols in each 7 symbols for NCP and every 6 symbols for ECP, the RS can also be located at the beginning. Thus, a shifted RS pattern can be applied.

In implementation (a), a UE 102 may be configured with 2 subcarriers for RS transmission within each DMRS symbol. Thus, an RB can be multiplexed with 6 UEs 102.

In implementation (b), a UE 102 may be configured with 3 subcarriers for RS transmission within each DMRS symbol. Thus, an RB can be multiplexed with 4 UEs 102.

In implementation (c), a UE 102 may be configured with 4 subcarriers for RS transmission within each DMRS symbol. Thus, an RB can be multiplexed with 3 UEs 102.

In implementation (d), a UE may be configured with 6 subcarriers for RS transmission within each DMRS symbol. Thus, an RB can be multiplexed with 2 UEs 102.

FIG. 23 illustrates examples of long PUCCH with one DMRS every 7 symbols for NCP. The same FDM combinations can be used on the pattern with a single RS symbol in every 7 symbols for NCP and every 6 symbols for ECP. In this case, the RS position should be the same as in DFT-S-OFDM based transmission, and no shift of RS position is needed. FIG. 23 shows several examples for a long PUCCH with a single DMRS in every 7 symbols for NCP with different UE multiplexing capabilities.

In implementation (a), a UE 102 may be configured with 2 subcarriers for RS transmission within each DMRS symbol. Thus, an RB can be multiplexed with 6 UEs 102.

In implementation (b), a UE 102 may be configured with 3 subcarriers for RS transmission within each DMRS symbol. Thus, an RB can be multiplexed with 4 UEs 102.

In implementation (c), a UE 102 may be configured with 4 subcarriers for RS transmission within each DMRS symbol. Thus, an RB can be multiplexed with 3 UEs 102.

In implementation (d), a UE may be configured with 6 subcarriers for RS transmission within each DMRS symbol. Thus, an RB can be multiplexed with 2 UEs 102.

FIG. 24 illustrates examples of DMRS allocation at frequency domain. FIG. 24 shows several examples of DMRS spreads in the frequency domain. A first example is for 2 RS per RB. A second example is for 3 RS per RB. A third example is for 4 S per RB.

FIG. 25 illustrates examples of UE multiplexing with different DMRS patterns. FIG. 25 shows several examples where four UEs 102 are multiplexed with different DMRS patterns. In FIG. 25, each crosshatch represents the DMRS pattern of a given UE 102. In FIG. 25, each crosshatch represents the DMRS pattern of a given UE 102.

A first example is for two RS per RB in the frequency domain. A second example is for three RS per RB in the frequency domain. A third example is for four RS per RB in the frequency domain.

FIG. 26 illustrates examples of frequency hopping for long PUCCH formats. To provide frequency diversity, frequency hopping of a long PUCCH can be configured. In this case, separate PUCCH regions or subbands should be configured for a UE 102, and the PUCCH can be transmitted with frequency hopping in different regions/subbands, as shown in FIG. 26.

A first example (a) illustrates frequency hopping at slot level or every 7 symbols for NCP. A second example (b) illustrates frequency hopping within 7 symbols for NCP.

FIG. 27 illustrates examples of self-contained DMRS patterns in each symbol. The UE multiplexing within a RB can be reduced or eliminated. Furthermore, DMRS of 1 symbol short PUCCH can be used in each symbol. FIG. 27 shows the reference signal pattern designs for 2 RS, 3 RS, 4 RS and 6 RS per RB. For each RS setting, at least two patterns can be defined, denoted as pattern 1 and pattern 2.

FIG. 28 illustrates various components that may be utilized in a UE 2802. The UE 2802 described in connection with FIG. 28 may be implemented in accordance with the UE 102 described in connection with FIG. 1. The UE 2802 includes a processor 2803 that controls operation of the UE 2802. The processor 2803 may also be referred to as a central processing unit (CPU). Memory 2805, which may include read-only memory (ROM), random access memory (RAM), a combination of the two or any type of device that may store information, provides instructions 2807 a and data 2809 a to the processor 2803. A portion of the memory 2805 may also include non-volatile random access memory (NVRAM). Instructions 2807 b and data 2809 b may also reside in the processor 2803. Instructions 2807 b and/or data 2809 b loaded into the processor 2803 may also include instructions 2807 a and/or data 2809 a from memory 2805 that were loaded for execution or processing by the processor 2803. The instructions 2807 b may be executed by the processor 2803 to implement the methods described above.

The UE 2802 may also include a housing that contains one or more transmitters 2858 and one or more receivers 2820 to allow transmission and reception of data. The transmitter(s) 2858 and receiver(s) 2820 may be combined into one or more transceivers 2818. One or more antennas 2822 a-n are attached to the housing and electrically coupled to the transceiver 2818.

The various components of the UE 2802 are coupled together by a bus system 2811, which may include a power bus, a control signal bus and a status signal bus, in addition to a data bus. However, for the sake of clarity, the various buses are illustrated in FIG. 28 as the bus system 2811. The UE 2802 may also include a digital signal processor (DSP) 2813 for use in processing signals. The UE 2802 may also include a communications interface 2815 that provides user access to the functions of the UE 2802. The UE 2802 illustrated in FIG. 28 is a functional block diagram rather than a listing of specific components.

FIG. 29 illustrates various components that may be utilized in a gNB 2960. The gNB 2960 described in connection with FIG. 29 may be implemented in accordance with the gNB 160 described in connection with FIG. 1. The gNB 2960 includes a processor 2903 that controls operation of the gNB 2960. The processor 2903 may also be referred to as a central processing unit (CPU). Memory 2905, which may include read-only memory (ROM), random access memory (RAM), a combination of the two or any type of device that may store information, provides instructions 2907 a and data 2909 a to the processor 2903. A portion of the memory 2905 may also include non-volatile random access memory (NVRAM). Instructions 2907 b and data 2909 b may also reside in the processor 2903. Instructions 2907 b and/or data 2909 b loaded into the processor 2903 may also include instructions 2907 a and/or data 2909 a from memory 2905 that were loaded for execution or processing by the processor 2903. The instructions 2907 b may be executed by the processor 2903 to implement the methods described above.

The gNB 2960 may also include a housing that contains one or more transmitters 2917 and one or more receivers 2978 to allow transmission and reception of data. The transmitter(s) 2917 and receiver(s) 2978 may be combined into one or more transceivers 2976. One or more antennas 2980 a-n are attached to the housing and electrically coupled to the transceiver 2976.

The various components of the gNB 2960 are coupled together by a bus system 2911, which may include a power bus, a control signal bus and a status signal bus, in addition to a data bus. However, for the sake of clarity, the various buses are illustrated in FIG. 29 as the bus system 2911. The gNB 2960 may also include a digital signal processor (DSP) 2913 for use in processing signals. The gNB 2960 may also include a communications interface 2915 that provides user access to the functions of the gNB 2960. The gNB 2960 illustrated in FIG. 29 is a functional block diagram rather than a listing of specific components.

FIG. 30 is a block diagram illustrating one implementation of a UE 3002 in which systems and methods for a slot structure of a long PUCCH design for 5G NR operations may be implemented. The UE 3002 includes transmit means 3058, receive means 3020 and control means 3024. The transmit means 3058, receive means 3020 and control means 3024 may be configured to perform one or more of the functions described in connection with FIG. 1 above. FIG. 28 above illustrates one example of a concrete apparatus structure of FIG. 30. Other various structures may be implemented to realize one or more of the functions of FIG. 1. For example, a DSP may be realized by software.

FIG. 31 is a block diagram illustrating one implementation of a gNB 3160 in which systems and methods for a slot structure of a long PUCCH design for 5G NR operations may be implemented. The gNB 3160 includes transmit means 3117, receive means 3178 and control means 3182. The transmit means 3117, receive means 3178 and control means 3182 may be configured to perform one or more of the functions described in connection with FIG. 1 above. FIG. 29 above illustrates one example of a concrete apparatus structure of FIG. 31. Other various structures may be implemented to realize one or more of the functions of FIG. 1. For example, a DSP may be realized by software.

FIG. 32 is a flow diagram illustrating a method 3200 for implementing a slot structure of a long PUCCH design for 5G NR. The method 3200 may be implemented by a UE 102. The UE 102 may determine 3202 the uplink control channel (PUCCH) format and configuration based on a signaling from a gNB 160. For example, determining the uplink control channel (PUCCH) format and configuration may include a long PUCCH format that supports more than 2 bits of UCI payload.

A long PUCCH may employ a format that includes a waveform, a number of resource blocks (RBs), a reference symbol (RS) pattern, and/or orthogonal sequences on RS and data symbols, and/or one or more control resource regions. RS symbols may be allocated at time domain, and orthogonal sequences are applied for UCI data at time domain or frequency domain.

The UE 102 may determine 3204 the DMRS locations in the configured PUCCH. DMRS of a long PUCCH may occupy fixed locations in a slot structure, or are relative to the starting symbol of a long PUCCH. If frequency hopping is configured or supported, a hopping location is also fixed based on DMRS structure.

Frequency hopping may be mandatory or configurable, and the DMRS of a long PUCCH may be determined per frequency hop based on basic building blocks. A long PUCCH may include one or two basic building blocks with the same length or a length difference of one, where each basic building block is configured with 1 or 2 DMRS following a pattern in the basic building blocks with lengths of 4-7 symbols. A hopping position may be determined at the middle of a given long PUCCH, and DMRS positions in each hop are determined based on the length of the hop from the basic building blocks.

The UE 102 may determine 3206 the uplink control information (UCI) multiplexing methods on the configured PUCCH. A common framework may be used on the RS location and UCI multiplexing methods. RS symbols may be allocated at time domain, and orthogonal sequences may be applied for UCI data at time domain or frequency domain.

If CP-OFDM is used, RS symbols may be allocated at frequency domain, and orthogonal sequences may be applied for UCI data at time domain or frequency domain. If CP-OFDM is used, orthogonal RS patterns may be applied for UE multiplexing.

The UE 102 may determine 3208 the resource of the control channel for UCI feedback. The UE 102 may transmit 3210 UCI on the selected channel.

FIG. 33 is a flow diagram illustrating a method 3300 for implementing a slot structure of a long PUCCH design for 5G NR. The method 3300 may be implemented by a base station (gNB) 160. The gNB 160 may determine 3302 the uplink control channel (PUCCH) format and configuration. For example, the uplink control channel (PUCCH) format and configuration may include a long PUCCH format that supports more than 2 bits of UCI payload.

A long PUCCH may employ a format that comprises a waveform, a number of resource blocks (RBs), a reference symbol (RS) pattern, and/or orthogonal sequences on RS and data symbols, and/or one or more control resource regions. The long PUCCH may employ a cyclic prefix Orthogonal Frequency Division Multiplexing (CP-OFDM) or discrete Fourier transform spread OFDM (DFT-S-OFDM) waveform.

The gNB 160 may determine 3304 the DMRS locations in the configured PUCCH. The gNB 160 may determine 3306 the uplink control information (UCI) multiplexing methods on the configured PUCCH. The gNB 160 may determine 3308 the resource of the control channel for UCI feedback. This may be accomplished as described in connection with FIG. 32.

The gNB 160 may receive 3310 UCI feedback on a selected control channel. A control channel used for uplink control information (UCI) feedback and a resource of the control channel for UCI feedback are determined by a UE 102 based on signaling from the gNB 160.

The term “computer-readable medium” refers to any available medium that can be accessed by a computer or a processor. The term “computer-readable medium,” as used herein, may denote a computer- and/or processor-readable medium that is non-transitory and tangible. By way of example, and not limitation, a computer-readable or processor-readable medium may comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer or processor. Disk and disc, as used herein, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray® disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers.

It should be noted that one or more of the methods described herein may be implemented in and/or performed using hardware. For example, one or more of the methods described herein may be implemented in and/or realized using a chipset, an application-specific integrated circuit (ASIC), a large-scale integrated circuit (LSI) or integrated circuit, etc.

Each of the methods disclosed herein comprises one or more steps or actions for achieving the described method. The method steps and/or actions may be interchanged with one another and/or combined into a single step without departing from the scope of the claims. In other words, unless a specific order of steps or actions is required for proper operation of the method that is being described, the order and/or use of specific steps and/or actions may be modified without departing from the scope of the claims.

It is to be understood that the claims are not limited to the precise configuration and components illustrated above. Various modifications, changes and variations may be made in the arrangement, operation and details of the systems, methods, and apparatus described herein without departing from the scope of the claims.

A program running on the gNB 160 or the UE 102 according to the described systems and methods is a program (a program for causing a computer to operate) that controls a CPU and the like in such a manner as to realize the function according to the described systems and methods. Then, the information that is handled in these apparatuses is temporarily stored in a RAM while being processed. Thereafter, the information is stored in various ROMs or HDDs, and whenever necessary, is read by the CPU to be modified or written. As a recording medium on which the program is stored, among a semiconductor (for example, a ROM, a nonvolatile memory card, and the like), an optical storage medium (for example, a DVD, a MO, a MD, a CD, a BD, and the like), a magnetic storage medium (for example, a magnetic tape, a flexible disk, and the like), and the like, any one may be possible. Furthermore, in some cases, the function according to the described systems and methods described above is realized by running the loaded program, and in addition, the function according to the described systems and methods is realized in conjunction with an operating system or other application programs, based on an instruction from the program.

Furthermore, in a case where the programs are available on the market, the program stored on a portable recording medium can be distributed or the program can be transmitted to a server computer that connects through a network such as the Internet. In this case, a storage device in the server computer also is included. Furthermore, some or all of the gNB 160 and the UE 102 according to the systems and methods described above may be realized as an LSI that is a typical integrated circuit. Each functional block of the gNB 160 and the UE 102 may be individually built into a chip, and some or all functional blocks may be integrated into a chip. Furthermore, a technique of the integrated circuit is not limited to the LSI, and an integrated circuit for the functional block may be realized with a dedicated circuit or a general-purpose processor. Furthermore, if with advances in a semiconductor technology, a technology of an integrated circuit that substitutes for the LSI appears, it is also possible to use an integrated circuit to which the technology applies.

Moreover, each functional block or various features of the base station device and the terminal device used in each of the aforementioned embodiments may be implemented or executed by a circuitry, which is typically an integrated circuit or a plurality of integrated circuits. The circuitry designed to execute the functions described in the present specification may comprise a general-purpose processor, a digital signal processor (DSP), an application specific or general application integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic devices, discrete gates or transistor logic, or a discrete hardware component, or a combination thereof. The general-purpose processor may be a microprocessor, or alternatively, the processor may be a conventional processor, a controller, a microcontroller or a state machine. The general-purpose processor or each circuit described above may be configured by a digital circuit or may be configured by an analogue circuit. Further, when a technology of making into an integrated circuit superseding integrated circuits at the present time appears due to advancement of a semiconductor technology, the integrated circuit by this technology is also able to be used. 

What is claimed is:
 1. A user equipment (UE), comprising: a processor; and memory in electronic communication with the processor, wherein instructions stored in the memory are executable to: transmit uplink control information (UCI) using a physical uplink control channel (PUCCH) format that supports more than 2 bits of UCI payload, wherein a position(s) in time domain of a demodulation reference signal (DMRS) for the PUCCH format is determined based on a length of a PUCCH for the PUCCH format, a starting OFDM symbol of the PUCCH for the PUCCH format, and a frequency hopping configuration for the PUCCH format, the PUCCH with only 1 DMRS does not support a frequency hopping and the PUCCH with 2 or more DMRSs supports a configurable frequency hopping, in a case where the length of the PUCCH is 4 to 14 symbols, the PUCCH with 4 DMRSs supports the frequency hopping between the position of the second DMRS and the position of the third DMRS.
 2. A base station (gNB), comprising: a processor; and memory in electronic communication with the processor, wherein instructions stored in the memory are executable to: receive uplink control information (UCI) using a physical uplink control channel (PUCCH) format that supports more than 2 bits of UCI payload, wherein a position(s) in time domain of a demodulation reference signal (DMRS) for the PUCCH format is determined based on a length of a PUCCH for the PUCCH format, a starting OFDM symbol of the PUCCH for the PUCCH format, and a frequency hopping configuration for the PUCCH format, the PUCCH with only 1 DMRS does not support a frequency hopping and the PUCCH with 2 or more DMRSs supports a configurable frequency hopping, in a case where the length of the PUCCH is 4 to 14 symbols, the PUCCH with 4 DMRSs supports the frequency hopping between the position of the second DMRS and the position of the third DMRS.
 3. A method by a user equipment (UE), the method comprising: transmitting uplink control information (UCI) using a physical uplink control channel (PUCCH) format that supports more than 2 bits of UCI payload, wherein a position(s) in time domain of a demodulation reference signal (DMRS) for the PUCCH format is determined based on a length of a PUCCH for the PUCCH format, a starting OFDM symbol of the PUCCH for the PUCCH format, and a frequency hopping configuration for the PUCCH format, the PUCCH with only 1 DMRS does not support a frequency hopping and the PUCCH with 2 or more DMRSs supports a configurable frequency hopping, in a case where the length of the PUCCH is 4 to 14 symbols, the PUCCH with 4 DMRSs supports the frequency hopping between the position of the second DMRS and the position of the third DMRS.
 4. A method by a base station apparatus, the method comprising: receiving uplink control information (UCI) using a physical uplink control channel (PUCCH) format that supports more than 2 bits of UCI payload, wherein a position(s) in time domain of a demodulation reference signal (DMRS) for the PUCCH format is determined based on a length of a PUCCH for the PUCCH format, a starting OFDM symbol of the PUCCH for the PUCCH format, and a frequency hopping configuration for the PUCCH format, the PUCCH with only 1 DMRS does not support a frequency hopping and the PUCCH with 2 or more DMRSs supports a configurable frequency hopping, in a case where the length of the PUCCH is 4 to 14 symbols, the PUCCH with 4 DMRSs supports the frequency hopping between the position of the second DMRS and the position of the third DMRS. 